Upgrading Windows 7 RC (Release Candidate) to RTM (Release to Manufacturing) was a common question in 2009. Because RC builds were designed to expire, moving the final release was strongly recommended.
Microsoft provided an official recommended method for upgrading, which required a clean installation.
Official recommended method
Microsoft required users to perform a custom install rather than a direct upgrade. The steps included:
- Backing up all important files
- Booting the Windows 7 RTM from a USB or DVD
- Choosing advanced installation
- Installing over the existing RC partition
- Reinstalling programs and restoring personal files
This method ensured the most stable and reliable transition to the final version.
Unofficial workaround
However, there was a workaround that allowed you to upgrade without wiping everything. This method was unsupported by Microsoft and could cause instability or leftover RC files, so the custom installation was preferred.
- Insert the Windows 7 RTM DVD
- Copy all files from the DVD to a folder on your hard drive
sources/cversion.ini
- Open in Notepad:
cversion.ini
- Change:
MinClient=7233.0
to
MinClient=7100.0
- 7100 was the RC build number
- Save file
- Run:
setup.exe
from the copied folder
- Choose Upgrade instead of custom
This method allowed the installer to proceed with an in-place upgrade from RC to RTM.
Modern context
As of January 2020, Windows 7 is no longer supported by Microsoft and no longer receives security updates. Running Windows 7 on internet-connected systems is not recommended.
Users should upgrade to a supported operating system such as:
- Windows 10
- Windows 11
Upgrading from Windows 7 RC to RTM was an important step for users in 2009 who wanted to move from a temporary test build to a fully supported operating system. Today, Windows 7 is a part of computing history, and if you’re revisiting it for testing or archival purposes, understanding the proper upgrade path helps preserve functionality and stability.