Windows 7 Unspecified Error whilst "Unloading the Box"

[Kruunkk]

Hi, I recently downloaded Windows 7 Professional 32-bit and when I run the "Win7-P-Retail-en-us-x86" it gets about a third of the way through "Unloading the box" when I get an error message saying "An error was encountered. Unspecified error". Does anybody know why I'm getting this message? If so, does anybody know how to resolve this issue? I'm running windows vista home premium 32bit if that helps. Cheers.