Cannot Extend my Network with Airport Express

I have an existing Airport Express that was used to Extend my network from my AP Extreme. It's now flashing amber, so when I went to see it in Airport Utility, it was no longer there. I had to reset my Express base station a while back, so it may have disconnect the 'extend'. I reset the express and then re-opened the Utility, I saw it and tried to configure it, but it failed. Now when I open the Utility (with the Express unplugged), the Extreme base station is not showing. if I plug in the Express, it's the only one that shows. Somehow the Extreme is working (even when Express is unplugged) and I have a wireless connection, but I still don't see it in the Utiltity even after doing a rescan. FYI - I run Windows 7