It's actually a good opportunity to ditch McAfee in favor of a less resource-intensive antivirus such as the MS Security Essentials, but you can download McAfee from the MyDellDownloads site if you really want to keep it. 
I bought Vostro 5470 so, with windows 8, so I hate win 8 and I will back to windows 7 ultimate, so when I bought the PC comes with MCfee installed I pay for the license 1 year, and don't come any serial key, the MCFEE was installed on my PC. Anyone know about this ?
I will change my windows, I will loss my McFee license ? 