Dell Optiplex 755 2007 CD/DVD player/reader help

You can use a half height drive for your system

Review page 59-60 for installation instructions.

https://dl.dell.com/manuals/all-products/esuprt_desktop/esuprt_optiplex_desktop/optiplex-755_user's%20guide_en-us.pdf

You have an MT?  Plextor DVD Burner on Amazon is my favorite.

if it is mt or dt, they both use standard old fashioned odd which has same form factor as PATA odd.  sata cables for such are standard and the same as those for sata hdd.  you can pop in any modern odd.

If it is SFF it uses slim odd which is standard in modern desktop these days if they still provide odd.  you can use a slim odd but front bezel of odd may look out of keeping with sff front bezel.

@bradthetechnut , OP has an OptiPlex 755 DT.

@redxps630 ,  I don't think there is a full height optical drive, only half height and slimline.

Chino is correct.  Half-height drives are 1+-5/8 inches (41.3 mm) high by 5-3/4 +inches (146.1 mm) wide, and are the standard form factor for CD and DVD drives in modern computers.

How am I supposed to keep the drive in? I received an original drive off of eBay, I go to put it in, but once I attempt to push the eject button or anywhere on the front it pops out. There seem to be no visible spaces to screw things into except one spot, the seller I received the screws from didn’t seem to keep it place, it fit but it didn’t fix my problem. The package came with 4 screws. I already had 4 screws slightly above where the hard disk drive goes, I don’t know what those do, but I apparently have no use for them. The old disc drive didn’t have a screw and I never had this issue except after replacing. Is it supposed to be put in a different way? I just pushed it down and slid it, it was good to go, but how do I actually lock it?

A solution was provided at the very first post with installation instruction.  Obviously it was not used.

To remove old ODD.

To install an ODD

Drive insert screws location

my mistake, I was only reading the newest comments rather than former. Thanks for the clarification