Now most of them might have downloaded the RC and you would be noticing that there is Watermark sayin “Windows 7 Evaluation Copy Build 7100″.Now this was just done for testing/implementation purposes.Now if you want to remove the watermark then BlogsDna posted some info.
There is a readymade script which does the job in 2 mins or so.You just need to run the script as Adminstrator priviledges and restart your pc the watermark will be removed.
Download Windows 7 RC Watermarker Remover
