I noticed you said you ran system restore and I assume the OS is on the SSD. Have a look here, Win 7 SSD set-up . I run without system restore and most programs installed on another Sata drive. Out of a 64 GB drive I have 37 GB free. Check the drive how full it is.
Occasionally I delete what's in the temp folder- C:/users//Appdata/Local/Temp. Anything it can't delete I skip.