If Windows Starts loading normally, but restarts before or about the time the GUI is presented, a Windows or other driver file may be corrupt, or the hardware it drives is faulty or there is some hardware conflict.
Reboot in Safe Mode by HITTING [F5] after the power-on self test (POST), as Windows is about to load. If Safe Mode works, the core of Windows is okay. Go into Device Manager – press the Windows logo key and [Break] together, then click on the Device Manager tab.
Open the branches and look for indications of trouble, particularly a yellow symbol containing an exclamation mark. If an item is shown as having a problem, disable it and restart in normal mode. If you can’t see anything, or that doesn’t work, boot again and this time tap [F8] or hang on to [Ctrl]. At the menu choose a logged start. After Windows has failed to load, return to the boot menu. Select Command Prompt Only and, when the prompt appears, type: ‘EDIT \BOOTLOG.TXT’. You will see a progress report on the failed start. It is normal for some entries to be marked as failures. Go to the bottom and see which files were loaded last. Even if success is indicated, these may be the trouble. Try to identify what they do. Knock themout by temporarily renaming them, or by disabling the hardware in question. [Alt][F] then [X] quits from Edit.
If Windows loads most of the way, and fails just before handing over control, suspect a program loaded automatically on start-up. Try holding down [Shift] during boot-up – this prevents these programs loading.
Next reboot to the command line, and type ‘SCANREG /FIX’. This checks for and possibly fixes registry problems. You can also try ‘SCANREG /RESTORE’ to revert to an earlier version of the registry, in case the current one is faulty. Before you reinstall Windows, go on-line and read KB article Q188867.
