i will use photoshop as a example
if photo shop is already installed
1. Back-up any files you want to save (from photoshop)
2. go into control panel > add remove programs
3. uninstall photoshop
4. run the set-up CD / Double click the installer
5.during install it will say choose directory by default this will be C:/program files/
6. change that to the desired directory E.G H:/programs/
(H being the external drive letter / PROGRAMS being the folder you want it installed in)
7. Complete installation.
If photoshop is NOT currently installed, START from STEP 4
............................................................................................Main System Spec: Intel Quad Q9550 (OC to 3.4Ghz), Gigabyte Ga-ep45-ud3l, 4gb kingston hyperX @ 1066mhz, Corsair tx 650, Nvidia 8600GT.