It does sound like you have a full admin account in the eyes of windows but the Netware stuff (which I'm assuming acts as a layer on top) doesn't seem to believe you to be a full admin in it's eyes. You don't need this Netware stuff and there could be other programs you encounter later on that cause you troubles.
if you want to do a full rebuild, do a few things first:
- Backup everything you think you'll need - documents, passwords, favourites, emails and so forth.
- Ensure you know what your graphics card, sound card, network card etc. are (Right click on My Computer >> Properties >> Hardware Tab >> Device Manager >> Find them under the appropriate category in here). You'll need this info to update/install the correct drivers later on.
- It might be an idea to download the drivers for your network card if you can do that. Just to make sure you can connect to the internet once the clean install is done.
- Make sure you have your Windows key!
Here's a guide for doing a clean install:
http://www.webtree.ca/windowsxp/clean_install.htm