Neet topic title....but, in computers there is nothing that happens at "Random". There has to be either programming or a physical cause for everything a computer does.
The standard home computer, never has been, is not now, or ever will be designed for 24x7 operation.
There are special "Server" models that ARE specifically designed and built for that kind of service.
Even a special OS, called "Windows Server" is written just for that purpose.
Our PC's are made out of the cheapest 'Hobby Grade' components, assembled by the lowest bidder (Usually Chinese).
Even Windows itself, was never written to be run 24x7. There are things that need to be done in Windows, like saving the active copy of the Registry, sitting in RAM, to the Hard Drive for permanent storage, that can only be done during a full shutdown and cold restart.
Before I ever started working on PC's, now 36 years, I worked on Mainframe Computers. With very few exceptions, those mainframes I worked on were shut down every night, if only for a few minutes. They called that "Bouncing the System".
That did a massive RESET to the entire system/network, which did bring everything up to date and improved performance.
I've worked on many PC's, that were used for receiving faxes, etc., where they needed to be kept running, but in almost every case, we programmed a "Reboot" into the Task Scheduler, for sometime in the early AM.
Also included in that reboot, was a routine to clean out temp files and other garbage collection. Even a weekly Defrag can be programmed into the system.
So a PC that is left ON, 24x7 needs some very careful setup, to make sure it does not load up with garbage and die!
Remembering still, that it was NEVER designed for that kind of service.
Good Luck!
TM