Removal of ';Security Update 7.1';?

My computer is infected with ''Security Toolbar 7.1'', and it is promts:

1. system is infected with trojan-spy.win32@mx; and to download antispam softwares.

2. I am having full updates of norton antivirus... but it is unable to detect this trojan

3. I can not restore my computer in back date also.

4. There is no infrmation about this toolbar even in ''add or remove programme'' in control panel menu..

I am having original windows XP home edition and a licenced copy of norton antivirus.

i dont want to spent any more to remove this ''Security toolbar 7.1''

Can anybody help me by telling the method to remove this spyware from my computer without spending money?

Please specify me any FREE removal tool or manual remove process.

all the links given in previos question detects the trojon but asking mony to remove it...

plz.... give some free removal tool of ''Security Update 7.1''

Removal of ''Security Update 7.1''?antivirus software

try the ''avast anti virus home edition'' with ''CCleaner'' removal....,it might help,free to download..

Removal of ''Security Update 7.1''?computer virus

Security Toolbar is a variant of the trojan Zlob/Smitfraud.

scans but repairs

shake away for squirrels