Jim, I was actually looking at another drive for programs as my current SSD is getting filled up (got a bit worried when I saw the C: Drive in red....11 GB remaining) and wasn't quite sure what's the best way to go about this.
Download TreeSize Free
and run it as administrator so you can see the whole drive (there is a portable version available too). Expanding the tree, you will easily find apps, data files, and pure garbage eating your drive. Be aware that your Celemony Separations folder can also get MASSIVE in short order.
For things "not garbage" (delete the garbage unless you collect it for a reason), you can move those to another drive (removing the original folder), then create junctions to map them back. Most "biggies" are in your Program Files, Documents, or ProgramData folders, and most have audio or video data files in them.
For me, my D drive is an SSD, and all junctions are made to the top level directory so I can easily find them. I got anal when building this new machine, so my C drive is roughly 100GB... so examples (that might apply to you) of junctions (these are the text entries in the batch files ... I use only command per batch and edit/resave them to a new name when I junction something else) are:
mklink /j "C:\Cakewalk Content" "D:\Cakewalk Content"
mklink /j "C:\Program Files\Cakewalk\Rapture\Multisamples" "D:\Cakewalk Content\Rapture\Multisamples"
mklink /j "C:\Program Files\Cakewalk\Dimension Pro\Multisamples" "D:\Cakewalk Content\Dimension Pro\Multisamples"
mklink /j "C:\Users\md_ma\Documents\Celemony" "D:\Celemony"
mklink /j "C:\Users\md_ma\Documents\iZotope" "D:\iZotope"
mklink /j "C:\ProgramData\XLN Audio" "D:\XLN Audio"
There are more, but you get the idea.
Caveat... if you use a batch file to xcopy data files regularly (advised), you will want to exlude those junctions so you do not copy them as well.
My xcopy batch file looks like (run daily and takes less than 10 seconds):
xcopy "C:\Users\md_ma" "d:\Backup\michael" /d /c /s /e /exclude:C:\list.txt
xcopy "C:\ProgramData" "d:\Backup\ProgramData" /d /c /s /e /exclude:C:\list2.txt
...and the "list.txt" file looks like this [edited to reflect the above junctions]:
"list2.txt" has this [also edited to reflect the above]:
another caveat is you need to save those list files elsewhere, then copy them to the main C directory, if you do what I did (they cannot be edited there, but in all honestly they can reside anywhere as long as they are properly mapped in the xcopy batch file).
Anyway, you get the idea... a lot of the things that reside on the C: drive (by default and you cannot change) can be dealt with in this fashion. The other upside is my C drive disk image can be created/restored in roughly 5 minutes.