spyware infecting my computer

suspect SearchMiracle problem

HELP! I am at my wits end! My computer is infected with spyware and no matter what I do I cannot seem to remove it.

So far I have followed all of the steps in the removing spyware article posted by Major Attitude. I was unable to to disable any of the three window services in step two, but two of the services were present.

I have downloaded and run all of the programs and downloads recommended.

The situation at present is - all spyware seems to be removed (via adaware and spybot) - I load up the internet and it goes to a normal home page. My virus detector (either AVG or McAffee) will then spot a trojan horse - at the moment it is backdoor-BDD (previously it was winshow.BG) and say that it has dealt with it. Spy pop ups appear on the screen (not many). The next time I log back on the internet it goes to the about:blank homepage but nothing appears on the screen.

Why does all the spyware scanners and virus scans come up clean, and then immediately I become infected again? I presume there must be some trojan horse infection that I have not yet cleaned out which is accessing the other files, but I don't know what to do to remove it.

I would very much appreciate some help as this is driving me MAD!

Regards,

Will