As you confess to not knowing a great deal about the inner workings, I wonder if you know of the "compatibility". ( Yes, I noted the thread title!) option.
If you do not, I would suggest you try reinstalling the program. There are two stages. First, right click the install (install.exe : p.exe or whatever). Now select properties. You will see a tab at the top of the window, "compatibility". Click this and in the next windows, select XP sp1 in the middle box and, in the samll square at the boottom, "run as Administrator"
When the program has been installed, find the executive file under "program files " in Windows Explorer. I'm guessing it will be under a folder named "Mass Effect". Follow the same procedure as above and see if you get any better results.