[kh99]

As the error messages says, you already have a table in your database named userregcode, so it fails when it tries to create it. If this table is left over from a previous install (or attempt at installing that mod), then you could drop it. But it's also possible that another mod is using he same table name, so you should be careful before you do that.

Maybe what you could do is use phpMyAdmin to see if the userregcode table has any data in it. If it doesn't, drop it then try your install again. If it does, then maybe you can rename it to someting else (like userregcode_save), that way if it turns out to be used by something else you can uninstall the mod and rename it to restore things.

Edit: Dave posted while I was typing, but we're basically saying the same thing.