You have a good rig. Have you downloaded SP1 for Vista from M$?
I was having CTDs from certain programs, as it was a Vista issue. SP1 has helped to stabilize the OS from causing CTD issues. This also included problems I was having with art programs, and my printer copier and scanner.
If you don't have it, you can get it here:
http://www.microsoft.com/downloads/d...DisplayLang=en
Also, have you tried adding the SH 4 .exe file to the DEP in the settings for your computer?
Right click on My Computer. The Control Panel/Systems window should open.
To the left under Tasks, go to Advanced System Settings
Click on the Settings Button in the Performance window
A Performance Options window will open
Click on the Data Execution Prevention tab
Make sure that it is set to Turn on DEP for all programs and services except those I select
Click on the Add button
You will have to navigate through your hard drive to where your .exe files for your programs to add to the list.
I was having problems with BoBII, CFS 3 with O.F.F. WWI add-on, and a list of other programs including SH 3 and SH 4.
In Windows XP, you could edit the Boot.ini file for Windows and turn DEP off entirely, but I've not found the same file for Vista, so I would be able to shut it off completely, and not have to worry about remembering to perform this little procedure.
I know this is a pain in the backside, but it may help if you haven't tried it yet.
Hope this helps with your computer ills!