Perhaps Microsoft is trying to save people from possible troubles with their Windows 7 upgrades, because they need as much good press as possible for this upgrade cycle. Perhaps they did not want anything that might have changed between the time of the Release Candidate to stay in use after the released version. Who knows. One thing appears to be certain, they aren’t telling us all there is to know about upgrades, and how many ‘scenarios’ might actually be possible. They did happen to let this one out, and not accidently, it seems.

Not that they are advised, but possible. I do a massive amount of reading about Windows, because I’m somewhat a trivia collector, but also because anything that can save me, or a customer of mine, time, is money in my pocket.

So when I perused the latest from Maximum PC, I was very interested to find that the magazine has a story that claims a proper path for upgrade from the Release Candidate to the RTM version. Unfortunately, I wiped the drive of the Release Candidate from my test machine, and simply switched back to Windows XP Service Pack 3 on another drive, so that I had a free drive when I did the install of the Windows 7 Enterprise version. So I can’t expressly confirm this.

However, I have never been led astray by anything found in Maximum PC; in all respects it is as reputable as any of the big magazines.

If I did have an RC version on a PC, I would back up the things I would want to carry across, just in case, and then try the upgrade in place. (if that is what you want – I would not, because at the very least, we do know that in-place upgrades take much longer than fresh installs)

Even though Microsoft’s official stance is that you can’t upgrade from the Release Candidate to the RTM/Retail version of Windows 7, it’s actually possible to do so using a quick, easy hack. This means that you can use the cheaper upgrade version of Windows 7, and do a “Custom Upgrade” to get a clean install. Or, if you don’t mind the risk of additional headaches down the line, you can do an in-place upgrade from Windows 7 RC to RTM. Here’s how to do it, in 7 simple steps

Step 1

Insert your Windows 7 retail disc into your DVD drive. Make sure to put the 32-bit installer disc in if you’ll be installing 32-bit Windows and the 64-bit installer disc in if you’re installing 64-bit Windows. If you downloaded an ISO from TechNet, simply proceed to step two.

Step 2

Extract all the files from the DVD (or ISO) into a folder on your desktop.

Step 3

Open the folder you moved the files to, then open the “sources” directory.

Step 4

Using Notepad, open the “cversion.ini” file.

Step 5

This file specifies which versions of Windows are eligible to upgrade. Right now it says the minimum client version able to upgrade is 7233—change this to read 7000 and you’ll be able to upgrade the beta or RC to RTM.

Step 6

Save cversion.ini, overwriting the old file.

Step 7

Install Windows 7 using these modified installation files. The easiest way to do this is by following our boot from USB guide. If you want, it’s also possible to create a new installation disc from these files using the free burner ImgBurn. You can find a guide on how to do this here.

Now, even though Microsoft has intentionally made this possible (and spilled the beans about how to do it in a blog post), they don’t officially support this kind of upgrade, and they warn that it may result in “some oddities,” so proceed at your own risk. Still, we’ve had good results upgrading this way, and it’s a heck of a lot more appealing than paying full-price for a standalone copy of Windows 7.

I’m not sure about all the aspects of what is controlled by the serial number in an upgrade, but I do wonder if it might possibly lead to a ‘scenario’ where someone has installed the RC, as the Windows 7 Ultimate version (why would you try anything less when it’s free?) and then when you do the upgrade, you install Windows Home Premium, yet some of the Ultimate features are left behind.

Where the unexpected results might come in is that the features might be there, but when you try to use them, the system does a check and sees the file version is not correct, stopping the whole process. There are a few other things I can postulate might happen, but I can verify none. However, if you are prepared to do a destructive re-install, with everything already backed up, and you have the time, why not give it a try?


A lifetime of happiness! No man alive could bear it: it would be hell on earth.

George Bernard Shaw

I’m sure we would all like to try to prove him incorrect!

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