After about 30-45 minutes of my computer being on, whenever i Ctrl alt delete and try to bring up task manager nothing shows up, the green icon will show up in the bottom right corner and even multiple if i hit the command more then once. And then, whenever I try to install/run programs after this point, they just lock up instantly! I have tried all the virus scan and adware programs and I have even tried system restore, but it always says your system cannot be restored to the point (tried several). Any suggestions?!