I have a desktop and a laptop PC (laptop, which is relevant to this question, is Windows 7), and as such I tend to want to play games on either or every now and then. As a result, I recently decided to put a bunch of games on my USB drive, installing them to the drive itself.

The problem I've found with this process has been that, with regards to Baldur's Gate and BG2 in particular, I can only get the Launcher to open, and when it does, it states that I haven't installed the games (even though they are actually installed on the drive itself). I tried to use a workaround, as some have mentioned on here, but I keep getting this message for BG1 (whether I run it as Admin or not):

An Assertion failed in D:\Dev\chitin\ChDimm.cpp at line number 581
Programmer says: Unable to Open BIF:data\SFXSound.bif

As for BG2, it gives me this when I try its BGMain:

An Assertion failed in ChDimm.cpp at line number 628
Programmer says: Unable to Open BIF:data\Hd0GMosc.bif

Any help would be very appreciated. Thanks.

EDIT:

I went and checked what the D: drive is on my laptop, and it's not the USB drive. For some reason, it's the DVD drive.

Open the file baldur.ini in your games folder. What does it say?

It should read when you scroll down to the install paths:
HD0:=E:\Baldurs Gate II
CD1:=E:\Baldurs Gate II\data\
CD2:=E:\Baldurs Gate II\data\
CD3:=E:\Baldurs Gate II\data\
CD4:=E:\Baldurs Gate II\data\
CD5:=E:\Baldurs Gate II\data\
CD6:=E:\Baldurs Gate II\data\
or whatever the install path of the drive is.

That's the first thing that comes to my mind to look at.

Also: are the games modded or do you play vanilla?

And are they patched or not?
If you have a disc version, you should apply the patches (not to be found on the Bioware site anymore, but you can browse for the patches at http://www.sorcerers.net/Games/index.php).
If you have the gog version, you should NOT apply patches, as it's already patched and when you do patch, the game will look for the discs again.

Probably about 16 months too late for this to be of any use, but as I've just had and solved this problem, and this thread came up in Google when I was investigating, I thought I might as well answer.

As the above alludes to, the baldur.ini file contains a list of where the data is supposed to be for each of the CDs. The trouble is, when installed on a removable device, the drive letter isn't a constant. For example, I installed BG2 to a USB drive whilst at home, where the USB drive was allocated Drive H, but plugging it in at work the same drive is Drive D. There may be a permanent fix for this if you have a better level of computer knowledge than me, but as a workaround, just go into the baldur.ini file and change the drive letters to the correct one for your USB drive each time you change computer.

Confirmed that editing the lines that refer to the "CD" drives in the baldur.ini file in your install directory is what fixes thsi error. Simply change the letter to match the new one it should be referencing from (e.g if the old location referred to 'D' as your CD drive and the new location is 'F', change 'D' to 'F' in every instance) and it'll run properly. Thanks!

This is awesome.

I have this exact same problem. However my ini file has the correct location.
[Alias]
HD0:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\
CD1:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\data\
CD2:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\data\
CD3:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\data\
CD4:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\data\
CD5:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\data\
CD6:=H:\GAMES\Baldur's Gate 1 & 2 [ no15 express] Gog.com GOOD OLD GAMES\Baldur's Gate\Baldurs Gate\data\

Is there a limit to the path

That's what you get for downloading and using pirated games.

Sorry to necro such an old thread but I am having this same exact issue/error just trying to run Baldur's Gate when installed to the regular harddrive. I've tried going into the ini file and changing all of the cds and hd0 to "C:\Program Files (x86)\GalaxyClient\Games\Baldurs Gate\data\" . Running Windows 10.

Not only did you necro the thread, but your problem is a different problem altogether. The title of this thread is "Running Baldur's Gate Off A USB Drive". Please make a new thread of your own, with an appropriate title.

It is but it isnt... im having the same exact error message, so I thought this would be better than making a redundant thread then getting pointed back to this one. As you wish.