When you turn on the laptop, it starts loading the operating system but then makes grinding noise and freezes. Sometimes the laptop works fine for a while, but on the next reboot, it makes grinding noise and freezes again.
Possible troubleshooting steps and repair solution:
Listen for the grinding noise. Most likely it’s coming from the hard drive area and it means the hard drive is failing.
If you still can boot to the desktop, back up all personal files as soon as possible and do not store anything important on the laptop. The hard drive may fail completely at any moment.
Replace the failing hard drive with a new one and reinstall the operating system from the recovery disc.