Problem in First run(Disk Request)

Hi

I was download Quartus 9.1 web edition and install it but when ever I want run it show me this error msg:

Title: SECSplashWndParent: quartus.exe - No Disk

msg: There is no disk in the drive. Please insert a disk into drive X:.

fortunately program start when i insert a disk into drive and press Try Again button .:confused: :confused:

So what's the Problem???.

Tnx.