unknown part for ASUS M5A78L-M/USB3?

[Dosson]

I was cleaning my PC today and found this strange part that fell from it. I thought it might have been from my motherboard (ASUS M5A78L-M/USB3), but I'm not sure what it is or what its suppose to do, cause the PC runs fine without it for now. To clarify why I might think it's from the motherboard is because when I was taking off the CPU cooler, I pressed my fingers on the blue "heatsink thing" then hear a snap. I checked the blue "heatsink" and noticed it was a bit loose, thou I'm not sure if it's suppose to be like that, as there are 2 nuts with springs holding it in place. after I've finished cleaning, the part just started moving inside the case after I placed it upward. All I'm asking is clarification on what this part is and is it of any important and I should do something about it or it's unnecessary.

images here --> http://imgur.com/a/z21Je

 

[Saberus]

It almost looks like a bit from the IO shield that was covering an unused port.

 

[Dosson]

is it something I should be worried about?

 

[Saberus]

If it's what I think it is, no.

But I would wait for others to weigh in. I could be wrong.

 

[norsestar]

I can't tell from the pictures how big it is but I'll guess ~10mm square. Unless it's tiny, it's too thick to be I/O shield but I think Saberus is on the right track. It may be some punchout from the case sheetmetal that was wedged somewhere and has worked itself loose. It could also be the back cover from the power or reset buttons.

If the system is working okay then I'd probably take a quick look for where it may have come from then throw it in a small envelope, tape it to the inside of the case, and not worry about it.