Vista to Windows 7 Upgrade fails with error 0xc0000359 and reference to iastor.sys

Microsoft has recently noted that Vista to Windows 7 upgrade process will fail and rolls back to Vista, if you are using a Intel Storage Driver iastor.sys. The following error message is generated:

\$windows.~bt\windows\system32\drivers\iastor.sys

Status: 0xc0000359
Windows failed to load because a critical system driver is missing or corrupt.

The main cause of this error message and failed upgrades is the incorrect versions of the iastor that are being referenced during the upgrade from Vista to Windows 7.

Till now, there are no update or hotfix available from Microsoft to resolve this particular issue. Users those are affected by this specific problem will have to manually resolve it to be able to upgrade from Vista to Windows 7. Microsoft has released the necessary steps required in KB 2008373. You will be able to find them included bellow:

1. Access Driver Repository Folder under C:\Windows\System32\DriverStore\FileRepository and move any folders that contain the file: iastor.inf to a temporary place.

Note: To move the files from the FileRepostiry you may need additional permissions which can be accomplished by taking ownership of the folder:

• Right-click on the folder and choose Properties
• Click Security tab.
• Click Advanced button.
• Click Owner tab.
• Click Edit button.
• Select your account.

2. Search for references to iastor within the oem inf files in the c:\windows\inf folder.

For Example: findstr /i /c:"iastor" %windir%/inf/oem*.inf

3. Make a note of the oem##.inf files reported where ## is a numeral.  Move the oem##.inf and corresponding oem##.pnf from c:\windows\inf folder to a temporary folder.

4. Delete $~bt, $~LS and $~Upgrade folders from c:\ drive if they exist

5. Download and install the latest version of the iastor.sys driver from Intel website on the Vista machine: http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=17882&lang=eng

6. Start the Windows 7 upgrade process. It should complete successfully now.

Note: Once the Upgrade process has completed successfully, there is no need to restore the iastore files, or the oem*.inf and oem*.pnf files back to their original place as the devices will no longer be needed.