How do I repair/renew IP number of my adapter?

Hello,
I recently upgraded from XP to Windows 7. Amongst several problems that I deal with, there is a problem of loosing the ip number when for some reason i have to reset the router.
Before, when I was using XP, this would not happen. I simply reset the routers (or the modem), and the system would not be effected, and would not loose internet connection. Even for some rare cases the local area connection was affected and there was only limited connection, I could open the Local Area Connection window, and from properties, i could give a "repair" command.
Now with Windows 7, every time i reset the rooter, the network connection is lost. I took it out "obtain an ip address automatically" and put it on "use the following ip" option. But still, the problem continues. The only way to gain access to the network again, is to reset the PC too.
Is there a command, like in XP, to repair the network adapter in windows 7?

Thanks.

It shouldnt be necessary, if you disconnect your adapter from the network and then reconnect windows should recognise this and change settings and whatever accordingly.

Also dont worry about what the icon tells you about your connections. Quite often it will show "Local Only" or "Limited Conectivity" on a fully working connection for a few minutes if it hasnt detected it properly.

If you're having network issues like this, I would go out in search of newer network drivers. First check the website of the manufacturer of your motherboard (i'll assume this is an onboard NIC you're using). If they don't have any newer drivers, find out the manufacturer of the actual NIC chip on the motherboard and try their website for newer drivers. 7 by itself is not the cause of constant router resets.

Thanks for all the answers.