tieyet :
Hi i have a 128gb ssd as ang a 320gb laptop hardrive as my secondary storage in my pc. My question is can i only put my OS into the SSD and the other applications/folders to my 320gb hardrive?
Yes, that is a viable scenario.
Backup all your data first.
Then do a clean install of windows to the SSD. (disconnect the HDD during this install)
Reconnect the HDD and format it, then install your programs and app to the HDD.
restore your backed up data to the HDD.
Done!
PS: You can't just move your programs and apps to the HDD, You HAVE to go through the install process so everything will work.