A random screw fell off and I can’t figure out where it came from

[serezha.seregin]

I was cleaning my PC, and suddenly a screw fell off. It is identical to a motherboard screw, however all the motherboard standoffs are accounted for. Are there any other places that use the same screws?
The motherboard is MSI B350 Tomahawk Arctic, and the case is NZXT S340 Elite (the screws came with the case)

 

[CountMike]

Could also be from a HDD although they would be shorter than for MB.

 

[serezha.seregin]

Could also be from a HDD although they would be shorter than for MB.

I’ve checked the HDD. The screws are indeed the same, but they are also all in place... I’m confused.

 

[CountMike]

Maybe just leftover somebody forgot inside. Happens to surgeons to forget tools inside patients.

 

[MicroT]

The places where screw may be present are:
Motherboard standoff connections
Graphics card/Pci plane mounts
Some cpu coolers
Hdd bays
Power supply mounting
Fan mounting
and some cases have screws for side panels or parts inside the case (Not common).
Generally if it isnt from the cpu or hdd there should be no problems and you shouldnt worry about it.