Moving photos to the D drive won't do any harm to your system. Freeing C drive will definitely improve the system performance. To improve the overall responsiveness of the system, follow the below steps.
- Move all data including photos and videos to the D drive .
- Download and run Temp File Cleaner from http://www.bleepingcomputer.com/download/tfc/
- Close ALL running applications as TFC will terminate them before attempting to clean up the temporary files.
- Double-click on the TFC icon.
- When the program starts, click on the Start button. TFC will terminate the Explorer process and all running applications and then begin the process of cleaning out all of your temp folders.
- When done, press OK to reboot your computer and finish the cleanup.
- Defragment your C drive
Read the instructions in the below link to know how to properly defrag your OS drive.
Another important thing you should do is Backup all photos to an external medium regularly. Hard disk failures are very common in today's systems so backing up the data is very important. Buy an external HDD and keep a copy of all your photos in it. You don't want to loose all your work in the event of a catastrophic hard disk failure.
Edited by Anshad Edavana, 01 June 2013 - 11:29 PM.