Tech Talk

[CK1]

like i said, without seeing the machine, it was an educated guess. having more information there are other ideas i can give you.

From experience my original answer is the most common solution. and actually, would fix any software issue (since everything is getting reset back to factory specs).

if you want to verify if you could have a virus without going through all the steps i mentioned and not loose your information (providing that there isn't something else wrong with the computer like a bad drive) you could plug the drive to a working computer with an up to date anti-virus and let it scan it. it can find and remove any virus, however, not undo any damage or changes it made.

the machine getting slow could be caused by heat. if your fans are not working correctlly or are dirty the machine could run hot and it could affect performance. but the drive could also be part of the problem or bad memory. if software is not an issue and your computer did not come with some diagnostics software (some brands like dell actually have a dedicated hidden partition with diagnostics that will check your hardware and does a good job of finding problem.) you might want to take it to a repair place where they can run tests on everything. most at home diagnostic software will do an okay job of detecting problems but aren't always the best.