Got a call this morning from a man who said he was from Microsoft Windows Service center and there was malware that had infected my computer. He was going to help me remove it. When I expressed suspicion that I would get a call of this sort, he gave me a call back number of 1-888-636-7290. He said that the security system that I use would not be able to detect of remove this malware.

Got a call, but no one was there. Called back and Verizon message said person was not available. Called back several more times, and disconnected after first ring. From Detroit, MI area. Caller ID said "Michigan Call".

Got a call from Toby Thomas and asked what his return number is (888-636-7290). Said he was with Microsoft Windows and that some users have been experiencing problems. I stopped him and said that we have an in house IT Department and that if there was a problem they can deal with it. Requested to be taken off their list and hung up. Be aware of these people. I was already aware of their scam, so I mess with them, but I have friends that aren't so intelligent, so they fell for it. They basically take over your computer, all of your information on it (which we all have personal info on our computers) and it will take hours for the REAL Microsoft to help you.

Got a call from a person telling me my Microsoft system was corrupted and he wanted to fix it for me.  I asked him for his IP address and he claimed he didn't know how to get it, I explained the procedure to obtain it and he said I would have to talk to a manager, I asked to be transferred and he said he could not do it and I would have to call 1-888-636-7290.
Told him I was recording the phone call and would need all information possible to turn him in, he hung up.  I tried to call the number and got an out of service recording.  Like Hugo's comment above, I am aware of these guys and love to mess with them.