Vista is not working!

Please help! My computer seems to have many problems and I have no idea what is causing them... no known virus, registry changes, etc. I can not access the internet connection (wireless) in normal mode. The connection is available in safe mode and internet explorer works. Almost everything that I do in normal mode freezes and has to be stopped using ctl alt del. Windows security center and firewall are off and can't be accessed (when I try to turn on security center in safe mode I get "the security center service can't be started"). In normal mode I can't access the control panel, network configurations, services, msconfig, other spyware programs (spysweeper, malware bytes), etc.. IE won't even come up and say that the page can't be displayed or anything. It "thinks" for a few seconds and then the rotating cursor stops (on some actions it will open a blank page and then freeze there "thinking"). Basically, anything that is associated with Windows or IE does not seem to work.

The desktop appears normal and I have full access to all of my files and 3rd party programs (AutoCad, iTunes, etc.).

I had OneCare installed, but uninstalled it in safe mode using the clean utility. I have run several spyware/malware scanners in safe mode and no infected items were found.

I am afraid that I am going to have to reinstall the OS. I have all of my files backed up, but I will lose a lot of programs, etc. if this has to be done.

Any ideas about what may be causing this or how to fix it would be greatly appreciated.

Welcome

If you follow these instructions, I am sure you will get up and running again. If when you first clean boot there is no effect, let us know.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7