Is there a standard name for the "standard" computer screw?

Most screws in a computer are UTS 6-32 screws. 6-32 screws are used for your power supply, 3.5" hard drives, securing expansion cards, and the case panels.

The other common screw type is the metric M3-0.50 screw, which are used for mounting optical drives, floppy drives, and the motherboard.

To make it harder, there are also computer cases that ship with motherboard standoffs that accept imperial screws, not M3.

It's amusing that both imperial and metric screws are used in each computer, and rather annoying that these screws are fairly similar in size (although not in threading). This means that an M3 screw will fit in a 6-32 hole, and will even seem to screw in, but it won't stay in place well. A 6-32 screw will go in an M3 hole if you try hard enough, which results in stripping.

Note that the self-tapping plastic screws used exclusively for fans and some lighting are also standardized, although they're just standardized within industry as "self-tapping plastic screws" rather than being a standard mechanical screw size.

6-32, and M3.

"Computer case screws"