Windows 7 Explorer Crash After Deleting File: Troubleshooting Tips for Windows 7 RC

So i was browsing my computer so i could go to my usb memory stick. I went to it and deleted a file. But after that the explorer crashed and i ended it. Then explorer closed so my taskbar went. I used ctrl,alt,delete to start run and get it up but then i could not open explorer windows. I could use internet but stuff like libary,control panel stuff wouldent load.

I havent gone back as im on vista now but what should i do to stop it happending.

Btw it was the windows 7 rc with all the latest updates.