Informatica 8 client / server on Windows Vista 7 : The install.exe needs to be run in compatibility mode (google for it)
Informatica 9 client / server works out of the box.
Let me know if you still face any issues.
I have tried the infa 9 from oracle on Solaris server and windows client, it's working fine having all the features of infa 9.
for aa complete list of features , look for release notes in informatica support.
Did you install the Informatica 9 PowerCenter which you have downloaded from Oracle? During the install didn't it ask for a license key? What did you do? Isn't there a trial version, how can I get it installed?