"File has an invalid digital signature"

The June CTP is live and we're excited that so many of you have downloaded it. Unfortunately, we've received several reports of users who get errors like this when they try to use the ISO:

Error 1330. A file that is required cannot be installed because the cabinet file c:\t\setup\winsdk-sdk_Core_SM_MLT-common.0.cab has an invalid digital signature. This may indicate that the cabinet file is corrupt.

That usually means that there was some corruption in the ISO when it got downloaded.

To verify that your download of an ISO file for the Windows SDK June CTP build is not corrupt, download the CRC Utility. (Note: this is not a Microsoft application. Use at your own risk.)

To run the CRC test, open a command prompt and run the utility. providing it the name of the file (i.e. crc c:\6.0.5456.3.0.WindowsSDK_Vista_idw.DVD.Rel.img)
The CRC utility will run two tests on the ISO: it will verify if the ISO is valid, and it will give the AutoCRC signature for the file. The AutoCRC signature for the Windows SDK June CTP ISO is 0x4F2680CF. You should also confirm the size of the ISO is correct: 1.13 GB (1,222,107,136 bytes)

If it fails any of these three tests, re-download the ISO. And if you continue to have errors, please email me with your log.