Sounds like your computer is slow and hanging up on a process.
It likley just needs some maintenence and possibly has some viruses on it.
You can use a program called CCleaner to remove all of the junk files filling up your computer, clean registry errors, and you can also limit startup items to help boot time.
You should also run a disk defrag once you have it at least booting ok
Another issue you might have is if your hard drive is over 90% full
You should also download malwarebytes and run it to scan and remove any viruses/malware