You can restore it to the factory condition and it would work like new unless there is a hardware issue.
Try Grif's scans at link to follow.
I got a Toshiba P750 with i7 processor baked with 8 gb of ram.
It takes half an hour to turn on, and it struggles so hard with opening and booting the programs. The mouse-animation starts going round and round easily when doing the easiest of things.
It strange because few weeks ago the computer literally could make eggs boil, and now it's really cold. The fan is running (I can hear it), but it doesn't heat alot, That could be because it can't start any programs barely. It has a 750HDD, with 120 left space.
I did a processor test with Intels own program and it worked completely fine.
What could possibly make this happen? Thanks for any help and suggestions, really appreciated.