I have a small SSD as my windows 7 C: drive. How can I transfer and save the Monero blockchain to another hard drive on my computer in order to save space?
In addition to pebx's answer, note that the default directory on Windows is %programdata%\bitmonero at least in v10.0. Move this entire directory to drive of your choosing and then run the command described:
monerod.exe --data-dir D:\desired\path\to\your\blockchain
If you ran Monero v.9.4 or prior, you can also save space by deleting the entire LMDB directory and re-syncing from scratch which typically takes a few hours on a fast connection with a modern computer. Monero v10.0 uses less space for the database.