Hijackthis tools is one of option that i use to prevent any unnessary application running on my computer. This tools can delete unnessary apllication running while startup. It will help you to delete them running on your computer.
What effect unnessary application running on your computer?
1) Your computer will take a time loading while startup.
2) It will slowing your computer and effected to your working on computer.
3) Some application is a spyware. It will disable certain option on your computer. Like Folder Option, you cannot open task manager, regedit will disable.
4) You cannot shutdown your computer properly.
So i suggest HIJACK tools to prevent all this.
Download Hijak tools from ..http://www.download.com/Trend-Micro-HijackThis/3000-8022_4-10227353.html
Follow below step:
1) Run HijackThis on your computer.
2) Scan what the application that running on your computer.
3) Disable / uncheck the unnessary application currently.
4) Then click on Fix Check.
5) Restart your computer and you will feeling differently.