Many problems that you face with your computer can be resolved - even if only temporarily - by restarting your computer. You may think this is a cop-out - but in fact restarting your computer is a very cost effective way of resolving some of your computer glitches.
Of course if a problem recurs every time your computer is restarted, then that problem needs investigation - but if a reboot solves even the occasional problem then it is worth trying first - and the best bit is - you can do this yourself!
*** The Exception To The Rule ***
There is only one exception I can think of to this guidance - and that is if you start hearing strange (and previously unheard) clicking and spinning noises from inside the computer. This could indicate an impending hard disk failure.
Many professionals will suggest that when you hear such noises you should turn your computer off immediately and seek professional advice - and they say this because you can lose more data the longer a failing hard disk is switched on.
They are right of course, but bear in mind that data recovery from a physically failed disk can cost several hundred pounds - you may prefer to keep the disk up and running and immediately start copying data to an external device.
Either way, it's your call, though if you took backup and disaster recovery seriously, it wouldn't matter...