Changing the OS is a major change to your computer. That will easily cause a new license reassignment which is allowed every 120 days. The "key" HL uses comes from Windows itself. So if the OS changes a new "Key" gets generated. So will major hardware changes.
Yes LW is a small company and does not work weekends. They will have you up and running again once the work week starts. My advice is don't do major changes to systems/computers when you need that computer for a game.
Don't be upset with a Small Company trying to make sure they get paid for what they do for living. They need to put food on the table and pay for places to live. Be upset with the community of gamer's who "think" its totally fine to steal what is not there's for free. Hell gamers have said "
We can buy one copy and share the software with the whole group" right in front of the LW guys at Gen Con. That is how little they think of stealing.
