Why does my network adapter have to be reset so often?

Have you tried updating your drivers? Running Windows Update might take care of this. Or just releasing/renewing your IP address might speed the process up.

Click Start, type CMD, hit enter. You should see a black screen. Type "ipconfig /release" and press enter. Then type "ipconfig /renew" and press enter. Don't type the quotes. Do these commands after switching from one network to the next or if the internet just stops working. Hard to tell what the problem might really be without more details.