- It crashed, that's possible. Usually there is no need to reinstall when it crashes. You start it again. So something is strange.
- You are unable to reinstall, but you didn't tell why. That makes it really impossible to help in any way.

For the slowness, go back to factory conditions as told in the user manual. Don't connect to Internet yet. Boot a few times into the default account to get it initialised. Wait till the CPU use in task manager is near 0% including the system tasks (such as initialising Windows Search or the antivirus scanning the hard disk for the first time). After that:
- How long does it take to get the Windows login screen?
- How long does it take to get the desktop of your account with all icons in the system tray (the right side of the taskbar) after typing in the password?
If those 2 together take more than 2 minutes on a pristine system, you surely have reason to complain.