How to upgrade from Win7 RC to Win7 RTM

How to upgrade from Win7 RC to Win7 RTM.

Microsoft has intentionally blocked the ability to upgrade from one pre-lease build to a newer pre-release build. With this block in place, one must do a clean install of the new build to upgrade.

Here’s what you can do to bypass the check for pre-release upgrade IF YOU REALLY REALLY NEED TO:

• 1. Download the ISO as you did previously and burn the ISO to a DVD.
• 2. Copy the whole image to a storage location you wish to run the upgrade from (a bootable flash drive or a directory on any partition on the machine running the pre-release build).
• 3. Browse to the sources directory.
• 4. Open the file cversion.ini in a text editor like Notepad.
• 5. Modify the MinClient build number to a value lower than the down-level build. For example, change 7100 to 7000 in order to upgrade from Win7 RC to to Win7 RTM. Here's a copy of the cversion.ini file after MinClient was changed to 7000:

[HostBuild]
MinClient=7000
MinServer=7100.0

• 6. Save the file in place with the same name.
• 7. Run setup like you would normally from this modified copy of the image and the version check will be bypassed. The upgrade option will be offered during the installation process.

A Product Key will be requested, but entry of one can be skipped, and the new installation will run normally without it for 30 days. The 30-day period can be renewed; see
<http://www.sctxca.org/suncity/clubs-groups/sites/computer/sigs/kfklatch/articles/Win7_120DaysFree.htm>.

This link suggests detailed steps on how to modify the ISO file. While you're at it, you might want to rename or delete the ei.cfg so that a choice is given for Win7 version as well as setting MinClient to a lower value.

I used the gBurner program to edit the Win7 Ultimate RTM ISO file and burned a new DVD directly from gBurner. Note that this has to be done for both the x86 and x64 ISO files if you need both.

Good luck, Dale....

(Win7_RCtoRTM.htm)