malware on my computer

In that case, just right click zzz.exe or Combofix.exe on your desktop, and delete.
And by the way, be sure to turn on Automatic Updates so you get Service Pack 3 for Windows XP.
(Control Panel, Security Center)
Support for SP2 installations will end shortly, and without SP3 you will be vulnerable to future infections with no real defense.

thanks have done that. do I need to delete any other of the programs which I installed such as tfc, rkill,rsit,rootrepeal or hijack this ?

You might want to keep TFC for occasional, very robust cleaning, but it would be a good idea to delete the others.

As this issue appears to be resolved, this topic is now closed.

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