Help!! Trouble with internet being hijacked!!?

PLEASE help me out someone...

Basically if I select some websites (usually from favourites/ bookmarks) I get hijacked to other completely unrelated ones. At the bottom left of my screen it'll announce briefly that I'm connecting to the site I've asked for, and then in a second it'll say it's downloading information from another site and load a different page.

I've scanned the system several times with Avast! and AVG but bad nothing shows up.

I've also switched from Internet Explorer to Firefox, but the same thing started happening within a couple of weeks.

Is there anything you can recommend to flush out whatever it is that's doing the hijacking and leave my browser in peace?

Simple explanations greatly received!

Cheers all.

Help!! Trouble with internet being hijacked!!?free spyware

Try running an anti spyware in Safe Mode, then using TweakUI from the Microsoft site to re-install your Hosts file by using the Repair Internet Explorer button.

Also, here's some software that will prevent browser hijacks in future;

Before attempting to remove malware you must switch off System Restore as back up files will be hiding in there, and it will just restore itself. Go to Start - programs - accessories - system tools - system restore.

Run your anti virus and anti spyware in Safe Mode. To get into Safe Mode repeatedly press the F8 key after the bios screen loads but before Windows loads. You'll know if you made it because the screen will be at 800 x 600 and your pc will be slow.