I'll know that the next time ;) But I wasn't suspecting at all a probably dying harddrive at first.
Concerning boot disc... if it's like for Ubuntu : I don't understand why, but I can't succeed in booting from a livecd.
Except if there is something new, I think I'll go with the usb adaptator and try to backup through my old laptop, this sounds like the safest way to go for now :)

I already tried (I tried to explain it in my OP), but it doesn't work ! At first I tried a live dvd : it lead me to something like this kind of errors. So I tried a live usb, first it didn't worked because I was pluggin the key on a usb3 port (if I remember well). After that, I tried again, taking care of making the USB compatible with EFI boot (I guess. I followed the same instructions than in your link ;)), and pluggin the key on USB 2 port : I see the "main" menu (try ubuntu without install, install ubuntu, ckeck disk for errors) but if I click on "try ubuntu", I see the black screen with a blinking cursor, which finally freeze and if I remember well two lights of my keyboard (scroll lock and caps lock ? can't remember) are continuously lighting on and off.
That's the first time the "live Ubuntu" failed totally for me, I always had it as a joker solution, here I don't get at all why it's not working :/ I only hope this is only due to my harddrive, and that nothing else is defectuous.
[I even tried the kaspersky rescue disc on a usb key : same, it doesn't work]
Now I prefer to listen all the advices, to stop trying anything anymore on my comp', and to simply try to plug the drive in usb mode when I'll get the adaptator : this should be the safest way to try to save the data.

Thanks for the suggestions both of you :)

You should use my solution on the laptop. Clonezilla is Linux based, but it should work. Why didn't your Ubuntu disk work? You mention EFI, but i have no idea what that is, and google isn't helping.

Computers are like people: sometimes they just die. From your description that seems likely. I've seen two hard drives dying in use, I think one (that started giving increasingly more errors) was due to bad electricity in the area (rural Thailand), and on my ancient DELL laptop, I think the internal hard drive died due to overheating.

So just try to get all your personal files etc. from the D partition to a safe place (e.g. connect it to some other PC with a SATA-USB adapter or such, and copy stuff to some other media). and then try to reinstall Windows 7 to a new hard drive.

Clean-installing Windows 7 may be a bit problematic, though. You can download Windows 7 installation ISO from Microsoft I think... but it checks your product key and tells you to contact your PC vendor, if it sees your Windows 7 product key is for a preloaded Windows that came with your PC, and not bought separately from a store.

When I needed to clean-install Windows 7 to a friend's laptop, in the end I had to download a pirate copy of Windows 7 ISO from a torrent site, and then install it using the legit Windows 7 (preload) product key, just because Microsoft is so damn dumb and won't let one download Windows 7 ISO from their site, if Windows was preloaded. With Windows 8.1 and 10 Microsoft has wisened up and lets you download the installation media from their site (using their Media Creation Tool).

Of course if those recovery DVDs/USB sticks work that you made eaarlier, that's all well and good I guess... but I've tried such recovery media twice (once with an ASUS laptop, and another time with a HP laptop), and it both cases they failed miserably. I have no idea why, but they just couldn't reinstall Windows. I had to clean install Windows from other sources in both cases.

Why would it be better than to simply plug the drive and copy the data ? By the way, I'm a bit afraid of the badly corrupted data : especially the system files, etc... is it a good idea to clone it ?
The live cd was working on my laptop, I haven't thought about testing the usb key. But I had the same kind of errors. See here, it was something like this (not exactly, it's a link I found when I encountered the issue) :
[ 33.375642] ata8: SError: { RecovData RecovComm UnrecovData Persist Proto HostInt PHYRdyChg PHYInt CommWake 10B8B Dispar BadCRC Handshk LinkSeq TrStaTrns UnrecFIS DevExch }
[ 33.375682] ata8.00: failed command: IDENTIFY PACKET DEVICE
[ 33.375698] ata8.00: cmd a1/00:01:00:00:00/00:00:00:00:00/00 tag 0 pio 512 in
[ 33.375698] res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x56 (ATA bus error)
[ 33.375736] ata8.00: status: { DRDY }
and unresponsive comp' which meant hard reset everytime.
And with the usb key, see here for more description.

For what I understood (remember I'm not very good with computer things), it's a kind of bios, which decide what to boot. I found about it and [url=http://www.techrecyclebin.com/2011/09/bcdboot-failure-when-attempting-to-copy.html]here because the mbr restoration wasn't working.
The wiki page for EFI. but I still don't exactly understand what it is and how it works :P)

Don't tell that, I like him ! :(
Can this be due to my computer power supply ? Maybe it's too old ? (my comp' is from 2010 I think)
I already looked and I should be able to download a full disc of installation from microsoft. But I don't know if my product number is for a preloaded one or a "real full" one, maybe I should try to download the image from microsoft and they'll tell it to me ? But if it's only a issue of getting an installation disc, that's not a big issue I think (that my serial wouldn't work with a clean windows 7 install, THAT would be a real issue).
For now, I'm going step by step : first buying adaptator and backing up data. After that, I'll see what to do with the drive and buying a new one, and after installing Windows.
I already use some recovery partitions and dvds on other computers (3-4 times I think) to do total restoration to factory settings with success (I had better luck than you it seems :P), it was even very easy I must say. But the harddrive was each time in good condition, and each time I was ready to wipe out entirely all data. It's computer world. Sometimes it's working and world is wonderful. Sometimes not.

Edit : I'm going to a local shop right now, buying the adaptator :)

@Splatsch,

assuming you've stopped using old drive. When your system is up and running again, there's some decent free recovery software available, so if the old disk is still spinning you should be able to save some or all of the data, but bear in mind that it won't have the original file names. Good luck!

Yes, I think it asks for the product key just before you start the download, and then complains if they feel you are not eligible to download the ISO from them, but you should get a recovery media from your PC vendor instead (which will cost you money, so it is just stupid).

However, who knows, maybe the vendor recovery media you made earlier works fine, and I just happened to have very bad luck twice (with two different vendors' recovery media)?

There used to be some 3rd party site (not a pirate site) that was providing Windows 7 installation ISOs earlier, Riverlake or Riverside or Digitalriver or riverriversomethingsomething, I assume they were up and running on Microsoft's permission... but some years ago MS apparently closed that site, no idea why. There is still an option to get an installation media from some pirate site (and use your legit Windows 7 product key to activate that installation), but there may be some hiccups there too:

- Trying to find a clean unaltered version of Windows. At least I wouldn't feel comfortable installing some altered pirate version, who the heck knows what kind of malware has been added there. I already know one case where such altered Windows 7 version had additional malware.

- If you want your own language version instead of English (French?), then you have to find that too. In my case I needed the Windows 7 Home version of the Finnish edition... but nope couldn't find it. So I installed the English Home version instead and activated it with the product key... but because it was the lowly Home version, it wasn't officially possible to change the OS language (that "privilege" is apparently reserved only for those who buy some Master Pro Super Ultimate Enterprise version of Windows 7, the stupid Windows world with its artifical usage restrictions). Anyway googling for it, I did find a way to change OS language also for the Home version.

For me it worked, the main issue was to obtain the right installation media (especially if you are after a non-English version). After I got it installed, I was able to afterwards activate the Windows 7 installation online, with the legit (preload) product key.

Anyway, I suggest you first try the vendor recovery media that you have already. I personally just lost my faith into "vendor solutions" as in both cases it didn't work for me, and I hated all those stupid artificial restrictions like "you can create a recovery media only once". Why the heck? So when that one recovery media (USB memory stick or DVD-R) gets broken or is missing, I have to pay the vendor for a new recovery media? Anti-piracy can't be a reason either since the recovery media is useless to others, unless they have their own legit product keys.

At least in Windows 10 you can easily download the installation media directly from Microsoft and clean-install it, which is what I just did to my relative's new Acer laptop. I got quite a lot of extra free hard drive space there as I got rid of all the preloaded crapware, and also could delete the useless "recovery partition".

Sounds like a good plan. Especially it is important you don't keep using the failing(?) hard drive, other than trying to copy stuff from it on some other computer.

Thanks :)
Well, if the "simply plug it and backup" plan doesn't work, I'll think about it at this moment ;)

Damn. Paying for simply having the installation disk of the software you already own and have paid for... Really ugly practice. And it's a second hand computer from... 2010 I think ? I don't know at all where its former owner bought it. I'll see what happens and will keep you informed in this thread ;) But as long as my cd key is valid, hopefully getting installation disk isn't the biggest issue (I'm more worried concerning the drivers :/ I never installed windows from scratch.). But still thanks for sharing your experience, that's always usefull :)
We will see, but if I buy a new drive, this recovery media will be useless anyway because I'll have to do a "clean" install from scratch :P I'll first try restore to factory settings with old drive, and see what happens (if disk seems like really dying). If I buy a new disk, I'll maybe try the recovery media, but I don't think it will enable me to install the OS to a new harddrive who doesn't have already some particular partitions (I guess). Certainly to "incite" to buy the latest windows version in same time as the new harddrive, or at least the windows installation media :P
There is this tutorial that I'm planning to use where they indicate where to download an image of Win7 : clean install of Windows 7 tutorial. They provide two links : one official from microsoft, one other from this site.

Yeah, I'm not too much worried about all of this for now. My situation isn't urgent : I have a laptop that I can use. It's old (9 years !) but enough for several days, even weeks in worst case. My priority is the data. Windows, well, when I see through what I went this last days, finding a windows installation disk doesn't scare me too much compared to the horror of massive slowness/unpredictability of the OS/corrupted system (or MBR) windows files and the fear of losing my data.
I'll see how it turns out and let you know :) (maybe I'm a bit too much optimistic, but we'll see XD)

I really hope everything will run smoothly concerning the "installation of windows" part [including getting installation media] *crosses fingers*

Yeah, I'll try and maybe I'll have some luck. But after all I saw since Friday, I don't think it could achieve any miracle on the failing disk :P and on the new one, I think it'll have to be a new installation, from scratch.
I absolutely agree with you. The "only one time" and this kind of restrictions (can't change language in Windows Home "simple" version ? Seriously ??) are really stupid and annoying, I hate them too because they're more often causing issue than anything else.
As long as you own a legal key, you should be able to (re-)install it !

Recovery partition saved me one time (one of the 3-4 times I talked about :P), so now I usually let it quiet, just in case : it doesn't costs too much harddrive space and can ease life. But I totally understand your reaction if you always had back luck with them !

Yep ! I'll try tonight to save my data, after meal :)

So I went to a local shop and asked them : it seems that it's a kind of "security" in the bios to prevent to "accidentally" install another OS (if I've well understood). In short it seems to be this who was making to fail all my tries with live dvd/usb of ubuntu and kaspersky (this and/or the harddrive who was struggling with himself).

News :
So, I went to my local store. I purchased this for 26.5€ (there wasn't a lot of choice :P).
Sellers where pretty friendly and answered a lot of my questions after I explained quickly my situation. I learned a bit their "services" prices : seems honest prices but way too expensive for my budget, so I'll continue with you & internet as much as I can (I have good hopes :)).
They told me that if I would have gave them my comp' to repair and backup, they simply would have done what I'm planning to do thanks to you : take the harddrive out and plug it with an usb adaptator to another comp'. So many money saved, thanks all (& internet) !

Question :
Tonight I'll try to dismount the harddrive and to put it in the case to plug it in usb : any recommendations/advice ? It'll be my first real manipulation of hardware. I know it's an easy one, but I'm still a bit afraid :P

Those are good. I used an ISO from Digital River without any problems. Just keep in mind for what version of windows is your current key on your dying drive. If it's for Home Premium, you can use it only on Home Premium... and so on.

After you are done with this ordeal, keep your important data in at least two places. If it's on your PC put it on external hard drive/memory stick. If it's only on external hard drive/memory stick put it on a second external hard drive/memory stick.
Good luck! :)

Watch some videos on youtube, that will help.

Okay ! So finding windows installation media is certainly solved thanks! It's home premium 64bits, I'll be cautious, thanks for the warning ;)

Yes, I'll be a lot more careful :) Losing data is a nightmare, I really want to avoid that as much as possible now XD
Thanks for the support :)

Good idea ! For now I found and [url=http://www.wikihow.com/Change-a-Computer-Hard-Drive-Disk]this. If I'm not wrong, I've got a SATA disk and I already took a look inside the comp' : doesn't look too complicated, I only hope everything will go smoothly.

From the manufacturer's website you can download drivers for your computer. Be careful to pick the right ones!!! Some drivers are better not taken from there but rather from the chip makers instead (many different chips on the motherboard and such.)

That's why I'm pretty scared when I'm thinking about it ! I'm afraid to do mistakes :S But... well... always time to learn :) With patience and thanks to help from people like you all other the web, I think I can do it. But first I'll try the recovery dvd, maybe I'll have good surprises which would avoid me this step ! And I have a dvd with the factory drivers (I remember I burned them when I got the comp', alongside the recovery dvd) so maybe I won't have to do the research ?
May sounds pretty stupid, but how can you know what are your components ? I mean, I know the graphic card, the processor but everything else... (and it's an old second and pc, so... I don't have a precise list, I should have made one when I still could access to windows :P).
And when you say "many different chip" : can you tell me some for example please ?
Any advice concerning this driver research ?

News :
So, I succeeded in plugging my internal drive with the usb case ! Yaaay ! :D
It was a bit more complicated than I expected -and raised some panic moments- because it was well fixed into a metallic structure, itself fixed to the rest of the tower (and you had to unfix the metallic structure first, but it was a little blocked by a plastic structure in front of the comp). But everything went well in the end, and I'm now more confident with the idea of manipulating a harddrive :)
The disk case seems not really of high quality or maybe I did a mistake while using it : when I close the case, the other side is a bit "pushed" because it's not totally (well?) fixed to the bottom and it's like if they didn't planned the harddrive would be this size but should be 1-2 mm less ?? Disk is well plugged in, and it's a 3.5", so I think it's simply a cheap fabrication (with high selling price :/). Of course I'll go again see this shop very soon to talk to them about this issue.
But well, I think it's mainly aesthetics (if you forget that it should prevent the disc from moving too much during a transport I suppose)(oh, and there are 4 bolts that should enable me to fix the drive to the structure, but the metallic holes of the case are a bit offset to enable me to do it) and so I tried to plug it despite that. The good news is that the disk is recognized !! Buuuut... The "not too bad" news is that it's slow. Slowly recognized, it seems to be always working (indeed, there are good chance it's sign that it's dying). But, good news again : even if it seems pretty slow, I can copy my files, and I already began :) Now I hope I'll be able to backup a maximum of things.
Work little disks, work.

Did you install the new hard disk in your computer and old HD in the external case? Then use the recovery dvd(s) on the computer with the new hard disk in it WITHOUT connecting the external, broken HD? THEN use the Windows (or whatever operating system you have, irrelevant) on the new HD to copy from the dying HD (that you of course have now connected)?

Best of luck getting all files that are important. Pity they are so spread out in Windows.

Use these progs to identify your components: and [url=https://www.hwinfo.com/]HWiNFO.