HELP! How to stop updates and restore system

[cowfrogs]

Hi!

My laptop has been working funny since last night and I really don't know what to do. It's not a virus though...
It all started when I downloaded Internet Explorer 8, my computer crashed and when I rebooted it automatically restored to its initial point: when I had Internet Explorer 7. However, for some reason, it didn't restore properly and now the system is really slow as well as working not properly.

1) whenever I switch it off/ switch it on it starts configurating 3 updates.... all the time

2) Internet Explorer doesn't work and I have to use Firefox or Chrome

3) Windows Mail won't let me write emails or typing text in replys, etc.

4) The system is really slow and bugged

5) also the stupid sidebar doesn't show the gadgets properly

HELP me please!

Thank you!