I got my Vista Business serial no free through the MSDNAA scheme. I have been using the o/s for over a month now. This morning, I restarted my pc, and at some point I noticed a small key on the taskbar. What? Activate windows? 3 days remaining?!?! After trying to reactivate online, I got the message that "the key is in use", and that I needed to purchase a new one. To cut a long story short, I found another guy's post on microsoft community, stating that after installing the nforce4 SATA driver published yesterday in Windows update, he had the exact same problem, and had to reactivate through the phone. That's what I did. And it worked. Now, I was told that this happened because a major hardware change occurred. No hardware changes were made to my pc. Absolutely none. The only SOFTWARE change was made last night, when I downloaded the nforce4 SATA update through windows update (thats why I restarted the pc before getting the activation problem). Isn't that ironic? Another legitimate user that wastes his time because of stupid protection systems. Anyone with a similar experience?