Cannot connect to hotspots after adding adhoc.

I have never had problems connecting to a wireless hotspot before till after adding an adhoc network (under preferred networks).

I wanted to get my Toshiba Laptop and my HP Pocket PC talking to each other by wireless lan. I used a simple setup by adding an adhoc network to the PC and was able to surf on my HP via Internet Connection Sharing and a dial-up ISP.

Well, it worked great. But the next time I went off with my PC and tried to connect to a wireless hotspot the laptop could not aquire an IP address.
I have tried reversing every setting I changed with the adhoc setup (including deleteing the adhoc network) but it never would fix the problem. Finally I had to do a system restore to get the system to work again.

This has happened twice and twice I had to do a system restore.

Any ideas why? There has to be a better way. Help!