I work at a security company now and we read a lot about this stuff. One important thing: be sure you absolutely know who that the "microsoft techs" are from Microsoft. One of the current scams is to "infect" your computer with something that says you need to call support at xxx.xxx.xxxx number but the support are actually the scammers.
I especially love the ones that call my house and say they are calling from 'windows computers" about my computer problem. Ha!
Anyone who has ever tried to actually call microsoft for support knows how tough it is to get a real person. I can't imagine they would call unsolicited. It's hard to believe that folks fall for this one still...