Complex server migration (cc4 to vanilla problems: rootkit + corrupted hard drive)
I am planning a server migration from an old CC4 server (win 2003) that has problems with a corrupted hard drive and a rootkit that seems to be contained but not removed.
I have installed server 2012 on the new server, setup the dns (increased the range and changed subnet so we can have more devices) and the DHCP, AD etc and tested it via mini network to be sure it is working.
The thing is i'd like to make sure that I have all the updates for windows, sql server etc and the easiest way to do that would be to use windows update but that would mean connecting to the old network. I have setup the new server to be on a different domain (as the schools have changed names), so is it possible to access the internet without interacting with the old server? Would there be a risk of the rootkit spreading to the new server?
Any thoughts are welcome,