re-assigning program to icons/folder to open when click

Beginner girl geek in over her head -- help appreciated.
Hi.
Using Windows 2000. Longed for less stodgy icons. Downloaded shareware icon changer. It did. Also made it so I couldn't click to open folder/drive icons.
Can open if I right click, get menu go down to open -- Over time, this is a zillion more clicks than otherwise -- in every folder, even layers down.
So, I uninstalled the program. Got old icons but still this problem (and Change Icon Folders still listed in right menu). When I click to open, get message that action not associated to program.
Icon changer customer service said clean out all references to program in registry. I did, using regedit & then another cleaning program. No change. Reinstall and uninstall, etc. didn't help.

Can anyone tell me how to re-associate whatever normally associated with desktop icons in Windows 2000, or do I have to reload Windows....... I know, should have backed up the old registry or never messed with changing until I knew more. ...

Any clue much valued.

 

Welcome to the forum. And it seems that you are learning the way all us old-timer geeks did. There may be a way other than the 'hard way' but dang me if I can figure it out.

First thing to try
start~run~sfc /scannow and you'll probably need your 2K install CD in the drive.

If that doesn't fix you up, what happens if you delete a shortcut icon and create a brand new one for the same app?