browser redirected to unintended site, Unable to download updates for antivirus

My OS is windows XP professional. I have Nortal antivirus( trial version) & Malware bytes installed.
My browser is directed to a website other than entered address.
My antivirus software,Malware bytes can't get updates -message I get is " please check if computer is connected to internet"
Also my firewall is turned off after every rebot.
Please help.

you a virus that i have come across before.

boot into safe mode (while booting press F8 like crazy)

go into the device manager (right click on my computer and go to manage.) once there go to device manager, click on view (up at the top) and click show hidden devices. On the right hand pane you should now see a section that says non-plug and play drivers. Hit the plus sign and look for the thing that says TDSserv.sys (might be minor spelling but you get the idea). Right click on it and disable it (dont uninstall it).

Reboot the computer into safe mode again and attempt to update malewarebytes, and this should fix your problem (but i would definately download another program superantispyware and run it also just to be safe.

hope this helps if not let me know.

I am unable to start in safemode... it freezes in the process

Moved to a more appropriate forum for some real help!

Malwarebytes will not update in safe mode. Safe mode is for troubleshooting and diagnostic purposes.

"While in Safe Mode, only specific programs and files needed to run the operating system are loaded. Some functions, such as connecting to the Internet, will not be active in Safe Mode and a standard video driver will be loaded causing a washed out look and a possible change in resolution. " (from HERE: http://www.pchell.com/support/safemode.shtml)

If you need to connect to the internet while in safe mode, choose Safe Mode with Networkingon the boot options screen.