After installing CS4 - what installation folders can be deleted?

I have successfully installed CS4 as a downloaded upgrade to CS3. Now I have the folder "Adobe CS4" on my desktop, 1.6GB. The subfolder, "Photoshop Content", has things worth saving, but the subfolder "Photoshop" looks like it was for installation only. Can I safely delete it?

Thanks

You may need it for reinstall, so move it to a backup folder and burn out a DVD.

Yes, it saves hassle if you move to a new computer.

Don't forget to register it with Adobe!

Thanks. Will do.