Changing to firefox does normally cure most browser issues......
If its an anti virus/spyware prob I would advise buying one....I never used to.....but then I never used to do online banking.....these days 25 quid a year for a decent anti virus/spyware program is money well spent....however if you dont do online banking then there are several free versions....namely avast and several good free spyware programs....see "computeractive" website for genuine liks to the free programs....