First of all please note a couple of things, I'm at work currently so I can't get specifics. Also, I've been trying to troubleshoot it over the phone, I've been at work a lot and I've only had ten minutes to mess with it. Lastly, I'm not bad with computers but I rarely have to troubleshoot issues so you may need to be detailed about how or what you're trying to tell me what to do.
With that said here's what I know:
I turned the computer off to go on vacation, come back and immediately went to work and my Fiancee got on but it was having all sorts of problems. I don't believe she was able to turn on the computer to mess with it, so I doubt she did it that day and it was working perfectly before I left. I doubt anyone messed with my computer while gone though, so it may have been dormant until it was shut down and restarted.
The problems I know of consist of:
Windows Startup errors, and failure to repair the startup.
Checkdisk running and saying certain files were unreadable.
Getting to a black screen with the mouse and nothing more before erroring out and shutting down.
After troubleshooting over the phone we got to this stage:
Computer boots up normally, but extremely slow.
Black background with the watermark in the bottom right saying it's not genuine.
Again, extremely extremely slow.
Security Essentials won't run, errors out.
System Restore doesn't have any restore points (which it should) and errors out when going into the menu anyways.
Running any program freezes everything.
Control - Alt - Del error after pressing it, the system said it didn't recognize it (or something like that)
My assumption is that there's a virus, not sure when or how, but that's all I can think of.
I can access the internet but extremely slowly, hence why I'm asking and typing this on my work computer.
Any steps and advice would be much appreciated.
EDIT: I failed to mention this. I'm using Windows 7 64 bit, originally I had Windows 8 64 bit but I downgraded (Wasn't a fan after continued use), however the problem comes in to play as I no longer know where my Windows 8 64 bit, or either of my Windows 7 disks are. So if it involves any of the installation disks to fix the problem then please notify me of that in your response, if need be I can find and buy an installation disk cheap from a retailer as I don't need another product key.
Edited by MrDeath126, 03 July 2014 - 11:51 AM.