Restart the computer to get back to the normal mode
If you are able to boot into Windows in the safe then try the clean boot procedure and check if it works.
To help troubleshoot error messages and other issues, you can start Windows Vista by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts.
Refer the below link to know more about clean boot procedure.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7