Vista has a built in security feature like OS X does, that certain actions require admin rights. What's happening is that when you try and run the 'ipconfig /renew' you aren't doing it in an admin setting. I don't have Vista in front of me, but you there is a Command Prompt box listed in the start menu (maybe under Accessories). Instead of left clicking on it, right click and choose to run as the Administrator. That should let you run the 'ipconfig /release' and then a 'ipconfig /renew'.

If you want to set a static IP address, then you should be able to do that by going into Control Panel and looking at the Networking section. Again, I don't have it in front of me, but you want to find the Network Connection/icon/etc for your the wired/wireless connection you want to use, open the properties, and find TCP/IP in the list. Opening the properties of that will let you select DHCP or enter a manual address.