|"....non starting cpu..."|
The term CPU is sometimes mis-used.
The case most of your computer components is in is NOT a CPU ! It's just a computer case !
A CPU - Central Processing Unit = the computer's micro processor, or processor for short. It's the most complicated integrated chip on the mboard, it usually is installed in a socket on the mboard and is removable (on some laptop mboards and on very few desktop mboards , it's soldered into the mboard), and the computer cannot work if it doesn't work.
If your cpu - processor - was not working, the computer would not start up at all.
The operating system not loading properly from the hard drive is a different subject altogether.
If your computer was not starting up you would not be able to run the spinrite CD on it, if that's what you're running it on. .
Using Spinrite won't help in the long term if the hard drive is failing ; it may not help in the short term either if the hard drive is in really bad shape.
"so if I loose all day that means I will have to work all night on the essay"
Spinrite takes a LONG time to run even on a drive that is not physically defective because it's very thorough.
If there are bad sectors on the drive, it will try to read the data on the bad sectors over and over and over again, to try to get a good enough read of the data such that the data can be transferred to spare good sectors on the drive. The time that takes adds to the intially estimated time Spinrite predicted.
Don't take any chances. If you can do the essay on another computer you have access to, do that while you're waiting.