Windows 7 - Unknown Error :(

HELP,

my PC has just recently cropped up with a strange error.

Basically my PC becomes very unresponsive with no apparent trigger, everything takes a long time to respond. This has happened around 3 or 4 times so far in the past week. The RAM and CPU seem unaffected ie running at idle speeds, so apparently not involved in slow down.

This leaves me with no choice but to restart, however when I do restart, the PC gets stuck on 'Shutting Down' screen and I need to resort to power button.

I am absolutely clueless as to the cause, any ideas?

in my opinion , there may be three reasons behind it .

First, there may be a malware . Do download malwarebytes and run it .

Second , there may be some programs not responding/ updates pending . Check in the progress tab in task manager if there is any updates pending .

Third, it may be due to ram . Remove it ... clean the front and reinsurt it . I hope it will work better after that .

this may help you troubleshoot your shutdown problem:

Analyzing Windows Shutdown Performance

but i would definitely start with a virus scan and a malware scan.