Here are the steps that the MVLS Administrator at your clients can use (or you if they have you setup as an external administrator for their agreement) to access their Windows Vista Enterprise bits for download if they have the rights to them through Open Value.
1) MVLS Administrators access MVLS site at https://licensing.microsoft.com/eLicense/L1033/Default.asp
2) Log in with correct Passport account
3) Click ‘Product Downloads’ (See screenshot below)
This is where they will find the software available to them for download.
Thank you and have a wonderful day,
Microsoft US Senior Manager
Small Business Community Engagement
This posting is provided “AS IS” with no warranties, and confers no rights