ProblemSolver - 5:19 pm on Aug 23, 2011 (gmt 0)

Hi designer,
If you install cs4 after cs5 it will end up creating problems in your computer, i agree with leosghost, first uninstall cs5, you can use any free removal tool, then you can install cs4 without any problems.
I would get Photoshop cs5 if i was you it's a great product, I'm using and i love it.