Hi. I was here last summer with this virus and now it's back again. No idea why or what causes it, but here's the problem: I have a Sony Vaio laptop with Windows 7 Home Premium 64 bit. My computer restarts every night at the same time. I just did a Microsoft Essentials Full Scan. I have the Win64/Sirefef.AB and Win64/Sirefef!cfg trojans.Please help!