Slotload DVD drives and half-size discs
I bought an acer aspire L320, and it's one of those PC's that has no DVD drawer: you offer the disc and it just slides in. I have a webcam I need to install but the software is on a mini disc. Will the machine take it in and spit it out when I'm done?
You should keep an adapter on hand.
I don't even own a slotloading drive, but I picked up an adapter when the store had it on clearance because I'm one of those "prepared packrat" types. It was something like $3. The term seems to be "CD single adapter".
Some slot load CD/DVD devices can accept smaller discs, but usually it requires an adapter. Some take them just as a 12cm disc, but that's more common in car CD/DVD players than PC CD/DVD readers.
Check the books for the PC, and if it doesn't say anything, assume you can't use small discs. If it says you can use them, it will also tell you how to use them (whether you need an adapter, etc).
Slotloading optical drives, as the DVD drive in the L320 is known, can't take optical discs that aren't of the standard 12cm size.
Half-size discs and rectangular, business card-shaped discs will not work - they may go in, but there's no guarantee they'll come out again. And if you can't get the disc out, you won't be able to put any other discs in.
Whoever made your webcam almost certainly offers the software you need in the form of a download, so you should still be able to install your webcam without the mini disc.