IE infection

, spy sweeperI have done something incredibly stupid, whilst being very busy
I had a pop up saying windows firewall had discovered ad ware please click
etc etc... without thinking i clikcked and now it seems something has
embedded itself into ie itself, as i am in my browser everything is ok then
every now and again the browser changes to the normal sex, drugs, penis
enlargement and hair piece malarkey, i have run adware sweeper, scanned with
pc cilan, symantec and bit defender these cleared so much junk but i am still
left with this ie problem, spy sweeper is saying that netssh.exe is on the
system but cant remove it, has anyone any ideas how to clean the system, any
help would be greatly apreciated.

best regards