Uninstalling An Old Version of Photoshop

Quite some time ago, I upgraded from v7.0 to CS3. All has been working well except one "inconvenience", I still have v7.0 installed and when I click on a .PSD the v7.0 version opens. - I had expected that when I installed the upgrade, it would have automatically uninstalled 7.0; or at least asked if I wanted to.
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What I want to know is how do I delete the v7.0 version without damaging my CS3 or losing any settings, add-ins, plug-ins, etc.?
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Can I simply go into the Control panel's Add/Remove and click the Remove button, or will that wipe out some things?

yes. use the control panel. if asked 'do you want to remove shared files?' say NO.

But, having said that, the two versions should be able to live on the same machine without any problems. Installing CS3 should have associated the files to it. Odd that it didn't, but, you can associate files to CS3 yourself.

In any folder, Tools>Folder Options allows you to do this.