Someone in a computer store messed around with my PC (windows XP) today to get it to run faster. But they must have switched off something crucial because I can't login to websites that need passwords now and I am just tearing my hair out because they didn't tell me exactly what they did, so I don't know how to reverse it.
I think they changed which programs begin on start-up, and I have used msconfig to see which ones have been disabled, but I don't know what any of them are as I don't recognize their names. Please help!