Well if your Desktop loads in Safe Mode, you can uninstall the Windows Updates that caused the problem from Add/Remove Programs in Control Panel.
Before you do this though, it might be a good idea if we had a look at what is running on your PC just to eliminate a malware issue.
Go
here and download the latest version of Hijack This. Unzip it and click on scan. Most of the files listed will be harmless and/or required so do not make any changes, just click on Save Log, copy it and post it back in this thread.
Also go
here and download Silent Runners.vbs to your Desktop (use IE) and run it. It generates a log too. It takes a minute or two and it will notify you with a popup when your log is ready. Please post the information back in this thread. If your AV queries the script, allow it to run. It's not malicious.
Both of these programs are small enough to fit on a floppy if you need to use another computer to download them.