I bought Bit Defender last year, and it causes odd problems with my operating system. Sometimes it runs when it is supposed to (2 a.m.) and all is fine. Other times it runs 8 or 9 hours and often locks the computer. Still other times it runs and afterward I have to restore the computer to the day before because otherwise all music stutters and everything takes forever. I have tried to get their help, and ran the diagnostics they asked for and submitted them. No reply. I asked again. Still no reply. Forget customer service. Today it said I had to renew the service. I didn't think it had been that long, but I went ahead, hoping the 2009 version would work better. After all kinds of problems installing the new version, it now tells me I have 145 days left on my license. Apparently I had that long on my original license? I intend to ask for my money back, but I don't have much hope I will get it.