if it's slow for start-up then type in msconfig in run and disable a few unnecessary start-up items

Avast! would be the best replacement for security essentials http://www.avast.com/store click the second from lowest selection for free version

have you checked to make sure you are on the latest Bios update for your laptop? i had a HP laptop with a fan issue similar and after updating my 2 year old Bios not only did the fan and cooling issue ...

It happened to me too when we switched modems

clear cookies, history, etc.

When was the last time it worked and did anything happen after the overheating (ANYTHING)?

You may also want to try Avast! (the #1 best free anti-virus software):http://www.avast.com/download-software
and/or CCleaner:http://www.piriform.com/ccleaner

No, when flashing bios,(WHICH SHOULD NEVER BE DONE UNLESS COMPLETELY NECESSARY) it must run without any problems and should be done with a UPS fully charged.
YOUR END PRODUCT: A dead ROM, which mean ...

Looks pretty sweet -Mr.Awesomesauce

Has anyone seen the model planes that look like fighters made by the Egyptians 10000 years ago, not to mention the pyramids and all the other crazy stuff that has gone on in history/