Disable "Restart on error" feature...
1. Right-click My Computer, and then click Properties.
2. Click the Advanced tab (Vista: click Advanced system settings).
3. Under Startup and Recovery, click Settings to open the Startup and Recovery dialog box.
4. Clear the Automatically restart check box, and click OK the necessary number of times.
5. Restart your computer for the settings to take effect.
You may see some error message. If so, post back what it says.
Also...
1. Click Start, point to Settings, and then click Control Panel (Start>Control Panel in Vista).
2. Double-click System.
3. Click (Advanced system settings link in Vista, then --->)the Advanced tab, and then click Settings under Startup and Recovery.
4. In the Write debugging information list, click Small memory dump (64k).
...and...
Open Windows Explorer.
Navigate to: C:\Windows\Minidump folder.
If you see any .dmp files, zip all of them, and attach zipped file to your next reply.
Vista users. You may need to copy .dmp files, paste them into some other folder, or desktop, and zip them there.