I'm still asking questions phaolo! It will be solved in a day or two, when I finally do the upgrade, if that's ok with you our master, of course :D

Hey, I was just puzzled and added a little joke :P

No prob. :)
Btw cotton swaps or no swaps? I saw someone doing it in a video, but I think they will leave lints. Saw two cloths for glasses or shiny surfaces, but they either not strike me as absorbing or that they will definitely leave lints.

You don't buy isopropyl in hardware stores :) Its a chemical, sold free by factories on places like ebay, or if you directly call them. Its priced about $2-3/Liter.

Same as amidosulfonic acid ($5-2/Kg), which is extremely efficient widely used descaling agent in professional service for caffee machines, washing machines etc. 1 spoon of amidosulfonic acid completely descales the kettle from limestone; take 10 spoons to descale the washing machine. :)

I wouldn't use cotton - I went with the fiber sunglass cleaning clothe. Soft as a babies bottom and didn't leave anything behind - and go easy with the alcohol - you only need a tiny amount. See what you can clean off beforehand just using the clothe and a light touch - then go in with the clothe, barely moistened like the slightest bit of dew on a summer morning blade of grass.

Yes!You probably mean mineral oil. Its completely electrically non-conductive, but highly thermally conductive. Its a pretty good method!

Unfortunately, you will still need regular thermal paste and CPU heatsink, because the thermal emissions on the cpu core are simply too high.

I remember that video, but afterwards they realized that it was hell to repair\maintain XD

Assuming my on the fly translation isn't off ( ;) ) I meant the microfiber ones (but mine weren't mossy - maybe a few odd "lint balls" but nothing glaring).

It rubs the thermal paste on the CPU cooler or else it get's the restart.

Actually, its just non-conductive cooling liquid. I think its better than water cooling (I have water cooled myself pretty long ago). but I can imagine it to be real pain in the butt if components are exchanged at least more often than once in a year. I'd say mineral is better than water cooling, because its really dust-free.

So I finally did it! :)

I used the small dot in the center method and after pressuring it with the heatsink I rotate it slightly left and right - I have to tell you i got quite surprised when I touchdowned the heatsink, because the contact didn't feel very hard at all :( (I hope I didn't apply too much, but even if I did the "expired" thermal paste should be non-conductive so I hope I'm ok) i was left even more curious after I locked the heatsink - it seemed that the asus m2n (or AMD boxed cpu) mechanism isn't so hard either - I was still able to rotate a few degrees left and right the heatsink (after I locked it to the motherboard)! Another surprise was that the cpu fan wasn't screwed to the heatsink but attached to a intermediate plastic border that was attached to the heatsink with a clips like mechanism I wasn't able to unlock - so imagine how "cool" was the heatsink cleaning without detaching the fan form it (no water allowed :)).
Have to say that Windows XP performed quite good for a change - it recognised the new cpu immediately, installed its drivers and needed only a restart to start working as it was before, and that's a migration from single core do dual core cpu! :)
Now while idle for a several minutes and cpu fan spinning at maximum (q-fan auto regulating function disabled in bios ) the 4850e temperature is around 40 degrees celsius. One program reported core1 temp as 40 and core2 as 30 which raised some questions if the thermal paste is evenly spread, so how do you think - did I managed to do the job good or i will be 100% sure when I step on both cores at 100% usage and enable the smart fan speed function in the bios?

Thanks for all the help friends, +1 to everyone in this thread :)

If it didn't spill around the edges, it's fine and not too much ;).

Peak temperatures are a clear indicator of how good a job you did, so throttle it up and see what you get. But, in essence, I wouldn't be too worried about the thermal paste coverage if your CPU stays below its recommended peak temperature at all times (ideally you'd want it to be at least 5 degrees below).

These temperatures seem normal for the CPU you are using . It is not unusual for core 0 to have a narrower range of observed temperatures than core 1, as it deals with with all the ongoing basic processes and services. If you want to check whether this is coherent , do alt-ctrl-delete and check the use of the 2 cores, if you see one busier than the other, and if that corresponds to the core that hs higher temps, then it's logical enough

With a large amount of anxiety, followed up by watching HWMonitor like a hawk for about a month.