Stop users installing programs

[subbass]

What are ways to prevent users installing apps like Skype, Dropbox, web browsers, toolbars etc..?

These programs do not require admin privileges as they install to their own profiles rather than Program Files. We use Win 2k3 at work so no Applocker. Software restriction policy in Group Policy is possible but someone who is a little tech savvy can just rename the exe file and then install.

Any suggestions?

Thanks.

 

[subbass]

Kaspersky.

The problem with blocking with file hashes is that (as far as I'm aware) it will be hard to maintain and keep up as programs are updated.

Any other ideas?