Internet Explorer problem

[Riever]

A friend is having problems with IE everytime they start the internet it keeps going to a page trying to sell them antivirus software, when they go to a different page it just keeps saying the page is blocked and goes to the virus software page.
They have deleted cookies and temporary internet files and also done a virus scan and still nothing and they just carnt seem to get rid of the page.
Any ideas?
Riever

 

[Coldzero]

Download and run spybot search and destroy, and malware bytes.

 

[bledd]

disable system restore
remove you 'av'
run ccleaner slim http://www.ccleaner.com/download/builds/downloading-slim
run nod32 trial http://www.eset.com/download/free_trial_download_int.php
run mbam http://www.malwarebytes.org/mbam-download.php
run spybot http://fileforum.betanews.com/download/Spybot-Search-Destroy/1043809773/1


still screwed?
run combofix http://www.bleepingcomputer.com/combofix/how-to-use-combofix


following this, stop going to bad sites etc

use firefox http://www.mozilla-europe.org/en/firefox/
install this addon for firefox https://addons.mozilla.org/en-US/firefox/addon/1865

when firefox opens following the restart, tick the 'Easylist' subscription