Problem updating Windows 7 solved

I don't know whether anyone else has come across this while trying to use the Win7 64-bit DVD to upgrade Win7 Professional, but while trying to do so by double-clicking the DVD icon in Computer (Windows) I was presented with the following message:

"An unknown command-line option [--silent] was specified."

Effectively, double-clicking the DVD accesses the autorun function, so the workaround for me was to open the DVD and go straight to Setup.exe, which seemed to work just fine.

I could only find the problem mentioned in one place (a Parallels blog) when I Googled, so I thought it might be a good idea to post my solution, just in case anyone else was having the same problem.