Where did you download the Windows 7 Operating System?? from Microsoft or Digital River??
Microsoft does iso. file and Digital River (I believe,
I could be wrong) just does a setup file.. or some other file format..
Were are you saving the Windows 7 OS( On your desktop, in a folder,)??
Because it sounds like it is JUST the folder you put Windows 7 in is a read-only folder..
I would just put the Windows 7 OS file on you desktop... and not into a folder..
Try that..
Hope this Helps...
EDIT: It appears this has been reported already and according to this Forum re-downloading the file may help...
Windows 7 student upgrade install problems