I followed the guide on the DOSbox website and the guide on the forums, But there are still errors coming up when I try to install

First, when I type MOUNT C OLDGAMES -freesize 700 It says Directory OLDGAMES doesn't exist. despite having a file on C: that's called OLDGAMES.

Also, When I type MOUNT D C:\DFCD -t cdrom -label Daggerfall It says MSCDEX: Failure: Drive-letters of multiple CDRom-drives have to be continuous.

If someone could explain what I'm doing wrong or how I could go about fixing this, I would be extremely grateful.

If you're trying to mount C:\OLDGAMES then write C:\OLDGAMES instead of OLDGAMES.

Not sure why you get the second error, though. You could try the official install instructions that are located in the DFInstall.zip file.