Guidance for upgrading to Windows 7 RTM

The purpose of this post is to help you start with a copy of the Windows 7 RTM code and upgrade an existing installation, especially if you installed the Windows 7 release candidate.

Note that this is not a detailed how to – there’s plenty of those on the Web already, and anyway it’s really not that difficult. Instead, this is a list of some of the gotchas that could put a spoke in the smooth ride that Microsoft promises but so often fails to deliver. Rule one: be patient…

1. Copy the installation files onto your hard disk. It’s faster than installing from a DVD and allows you to make a small tweak that you’ll need if you’re upgrading from the Windows 7 RC (release candidate) as I did. Even better, install from a second hard disk or a USB stick, as this will speed things further.

2. Get a proper copy of the OS and check the files are all valid. If you don’t do this, you could get a third of the way through the process only for the installation process to throw up an error because it couldn’t read a file. That’s annoying.

3. If you’re upgrading from the release candidate of Windows 7, then you need to make a small alteration to \Sources\cversion.ini, as an in-place upgrade, as opposed to a fresh installation, is not officially supported. However, it does work without problems if you do the following:
i) Open cversion.ini with Notepad. This is what you’ll see:

ii) Alter the first line so it reads:

iii) Save the file. That’s it.

4. Start the installation and load up your patience.

5. After a few prompts, the system will tell you that it doesn’t need your attention: effectively, it’s telling you to go away and come back in a while. If you’re upgrading an existing installation, that timescale is longer than you think. I left it running overnight and it took over six hours to copy across an installation of several hundred gigabytes. Don’t be tempted to reboot if it seems to be doing nothing at the start of the ‘Transferring settings’ section.

6. If you do reboot before the process completes, check the logs in the c:\$WINDOWS.~BT\Sources\Panther folder, especially setupact.log, to find out why it failed. There’s a workaround available here for an installation that gets stuck around 61%-62%. The system should then roll back to your original OS – it worked three times for me after rebooting at different points in the installation process, despite the dire warnings about doing so.

7. Why might you want to do this?
i) Your Win7 RC licence key runs out in June 2010
ii) The release candidate manifested a few glitches
iii) The release candidate certainly included some debug code, slowing things down.

Each of these three reasons is a good one to get onto the RTM code asap – together they’re compelling. Unless of course you decide that Windows 7 is not for you and you want to go run Ubuntu…