1. Turn on the computer and begin hitting the 'F8' key when you see the BIOS screen. This will take you to the Safe Mode menu. Use the arrow keys to highlight “Safe Mode,” then hit 'Enter' on your keyboard. This will boot your computer in Safe Mode, a minimalist manner of operating Windows that runs only essential Windows files.
2. If using Windows XP in Safe Mode, click the 'Start' button and then click 'Run.' In the box that pops up, type “msconfig” and hit 'Enter.' If using Windows Vista or Windows 7, click the Windows logo in the bottom left corner of the screen, type “msconfig” in the search field and then hit 'Enter.' This will open the System Configuration Utility.

3. In the System Configuration Utility box, click the 'Services' tab, check the box that reads, “Hide All Microsoft Services,” click 'Disable All' and then click 'Apply.'
4. In the System Configuration Utility box, click the 'Startup' tab, click 'Disable All' and then click 'Apply.' Next, click the 'Close' box. A box will pop up that prompts you to restart your computer. Select 'Restart' and let the computer restart itself, allowing it to boot to Windows normally.
5. If the computer still stalls when trying to boot to Windows, restart the computer and boot to Safe Mode again. Run your antivirus program in Safe Mode, deleting any files that are flagged as viruses, spyware or malware. Restart the computer and boot to Windows normally.