GTA: Vice City [Steam version] broken - can't save. Any ideas?

Close the game, find and delete your save file (and disable cloud if used by the game), then start up and try again.

Thats about my only idea for a fix.

Any chance you've got a period in your windows username?
If so then that's the problem, GTA SA has the same problems btw, another option could be that your user permissions block the game from creating the save file/folder.
If that doesn't help there's some guides on modifying the .exe which was originally intended to fix corrupted save files but it has fixed the problem you're mentioning in some cases as well, I would save this option for last however since you'll probably need to do some proper research on how to do it before attempting it.

Try deleting your gta_vc.set file, which should be located in (assuming you're using a Windows OS)...
Documents and Settings\username\My Documents\GTA Vice City User Files
At times the file becomes corrupted or is set to use a distinct save-location than desired which leads to this issue, among others. The game will create a new file on reboot; I should warn you that this will also reset your controls to the default.

When Vice City was released on the pc it was still basic no cd checks back then,so the DRM was hardly an issue,and steam version if anything uses whatever steam uses i would assume.

I have had no issue saving or playing my steam version although the controller support is lacking a decent lay out and i hate using the keyboard that is my only major gripe.

Would it be chance trying to hard save to C:\users\mknowlton\My Documents by chance despite %userprofile% not being on C?

That may be your issue as last i knew it would only save to the c: drive,but it could have have changed since then.It still worth a shot and mentioning.

That is why i always make windows on the C: just in case of things like this as i know a couple steam games will not function unless they are on C:

anyhow good luck

Hmmm.

A cracked "no CD" exe file seemed to fixed this... I feel kinda dirty now :/

Thanks for all your help, folks :)