1) Search (Windows folder) & Modify this file "sysdm.cpl" with exescope or Resource hacker I use Resource Hacker
2) Replace the two bitmaps u see in Resource hacker with ur own bitmaps. Create two bitmaps one 256 color and the other 16 color and then replace.
Save the changes.
3) After modifying backup the old file and replace with the modified file in these two folders since it is a protected file. Order is significant !
X:\WINDOWS\SYSTEM32\dllcache
X:\WINDOWS\SYSTEM32