My windows 10 ssd is pretty small so I had the idea to install programs on a 2nd drive. What's the best way to do this? Simply pointing the installer to another drive doesn't put everything there (Sonar puts Dimension & other content on C:\ with no option).
 
Can the C:\Program Files folder be redirected to another drive letter?
 
Can the C:\ drive be extended to another drive? (tried this in disk management but not possible)
 
Options?

There is an option for the Content Path in Command Center Settings > Paths

soens
 
Can the C:\Program Files folder be redirected to another drive letter?

It can be done, but I wouldn't recommend it.
 
This ought to help...
 
http://forum.cakewalk.com/Moving-audio-libraries-for-Soft-Synths-to-different-hard-drive-m3360245.aspx

By other programs do you mean Sonar, or other stuff?  I have all of my applications except Sonar installed on my internal 1TB drive D.  My OS and Sonar are on my SSD C.
 
I have no issue running anything.

Generally even a 128 GB SSD will be enough storage to hold all your apps and it is defiantly recommended all software be kept on C drive.
Then the content and samples are put elsewhere.
I have a lot of software installed to my C drive and it's sitting at about 62 GB.
But I do housekeeping especially after running CCC.
I back up the Sonar downloads folder to my H drive and delete everything. That folder can get real big.  I've yet to have to roll back so cannot comment on how easy this would be.

Was intended for all programs not just Sonar. I realized after buying my laptop that 128GB main drive is about the dumbest thing they could do to a computer. I run countless programs and it fills up too quickly. I will probably have it migrated to a 300+GB.
 
All DAW projects, info, etc are kept on a separate drive though I will see to moving the content folders there too.

For programs other than SONAR?  I have many that are stored on other drives.  I have Program Files and Program Files(x86) directories on 3 drives other than C
 
For me, which drive to install on comes down to two factors; will they operate correctly on another drive, and how quickly do I want the program back if I need to restore.  These are secondary to me wanting the smallest possible C image that contains the programs that would take the most effort to reinstall and get tweaked back to the way they were.  That makes SONAR and VSTs no-brainers for C.  Everything else can be scattered hither-dither AFAIC
 
For installation on other drives, I just change the drive letter in the path presented for install.  I have had zero problems with anything I've installed on different drives.
 
Note that I have a nightly backup job that runs on all drives.
 
I have projects on a separate drive and content on yest another drive along with sample libs.

I've been reading that making the program files folder other than c: drive isnt always good for windows 10. And tho you can redirect some stuff during install, not everything goes there. I have to physically move stuff afterward. Guess thats my only option for now.

Aside from relatively quick loading of Windows and applications, the performance gains of an SSD to store those programs is exaggerated. Most applications load from the drive (slow) but run primarily from RAM (fast). If you have enough ram to avoid constantly writing to virtual memory, an SSD is not a big deal. You can find a 1TB hard drive  for under $50.00, about a sixth of the price for an SSD that size, and the time you save by fast booting from an SSD may well be negligible compared to trying to shoehorn your applications into a small SSD boot drive. 
 
If your C: drive is limited in size, then rather than "extend" drive to a larger platter drive, you can use symbolic links to fool your system into thinking things that are stored elsewhere are actually located on your C: drive. Of course doing so will negate the illusory performance advantage you imagine you have achieved by using an SSD for C:. 
 
http://www.howtogeek.com/howto/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/
 

The problem with installing programs on other drives it may not prevent the installs from installing support files on the C drive. There are App Data folders and program data folders that are on the C drive. Its possible that the support files may be a larger install then those in the program folder.