I used to have similar problem with my Windows Vista. Luckily one of my friends have had similar problems with her computer and she advised to me to secure a reliable professional registry cleaner software.

Apparently Vista is graphics loaded and needs more computer resources compared to other operating system. Given this it is important to always optimize computer to prevent problems. By employing a reliable registry program I was able to clean my computer system and eliminate obsolete and unnecessary files thus preventing all these operating system problems.