Acquired this computer from a friend about a month ago. Custom built, but has a few parts that are a few years old, not a big deal. When I received it, I added 1 more gig of ram, a TV tuner card, and tried to install an additional video card to no avail. Moving on, after all was installed, all was great.A few days later, when I did the usual reboot before I retired for the night, and when Windows booted up, I could not log on to either Admin enabled account. The guest account was / is enabled and is the only way to log on to Windows. I have read several forums, and so far none of the remedies and suggestions seem to work. I'm pretty good, knowledgeable wise, but I'm no engineer. Please, if someone out there can give me a hand in "laymans's" terms, I'm willing to figure this out too. Thanks... Tom