why does sometimes when i exit my internet browser it opens a shit load of

Sounds like you have a virus.

Allow Microsoft to conquer that one for you!!

Just run a scan with the Windows Live OneCare Safety Scanner and IT WILL SURELY RID THE VIRUS/TROJAN,etc..

Google it: Windows Live OneCare Safety Scanner
or
Here's the direct link:

http://onecare.live.com/site/en-us/default.htm

Or you can go there for your self; by taking this route;

Go to www.microsoft.com
Security & Updates tab click for Home Users
Next, Under the Security Products bar located to the right of the screen, select Windows Live OneCare or Windows Live OneCare Safety Scanner.

Spy-ware or Virus same thing, go to your Start Menu > Run > Type msconfig, go to Startup tab, disable all services, also in msconfig where it says Services Tab, anything that is not Microsoft Corp. disable, then restart computer, that should stop it, if not you should download or install some Antivirus Software like AVG or Norton Antivirus.

you have a virus...

More information is needed to answer this question.

With these limited information you provided, my best guess is Viruses or Spywares (most likely Spywares)

What do those internet windows show? Bunch of Advertisements or inappropriate sites? if it is, I can be certain that its spyware.

Give your computer a good scan with an antivirus and antispyware program should do the trick. Try AVG. (google it)