For a long time it never even occurred to me that I could change the default folder that applications installed to on my computer. All of the applications I was installing all asked where I wanted them to install and I simply over-typed the C with a D in order to install the application on the D drive. Of course I sometimes has to select to do a Custom install in order to be able to choose where to install but then I always choose to do a custom install when offered that option just so that I can see what it allows me to choose.
The first few programs that I came across where they didn't offer a choice of where they should be installed were utility programs which extended the functionality of the operating system and therefore could legitimately be considered to need to be installed into the specific folder on the C drive that they installed themselves into.
The first actual application program that I came across that didn't allow you to choose where to install it was Google Chrome. When installed from an account with Administrator access this browser installed itself as if it were an operating system utility. When installed using a user account without administrator rights it installed onto my E drive as if it were part of my data. As an application, neither of these locations for the install was appropriate. I then discovered a "portable" version of Google Chrome that rectified this problem and actually asked where the application should be installed so that I could tell it to install as an application on the D drive.
The second application that I came across that didn't ask where it should be installed was "TweetDeck 2.0" and in this instance a portable version wasn't available. It was while trying to find a workaround to get it to install in the right place that I was reminded that there is actually a registry entry that defines where the default install folder can be found. Once I changed that registry entry I was then able to successfully install TweetDeck into the correct folder on my system.
To change the default install folder for your Windows operating system you need to run the regedit program using a login that has administrator access. You then need to go to:
In the right pane you will see an entry labelled ProgramFilesDir. Simply modify the value associated with that key to point to your desired default installation folder and save the update.
Since applying this change I have discovered that doing so breaks Windows Update as soon as it finds an update to apply to the operating system. The only way to get the updates to install is to change this value back to its original value. This means that the only way to actually make use of this to install rude programs onto your computer that fail to ask where they should install themselves is to manually update this registry entry setting immediately prior to the install and then set it back immediately afterwards. You then need to make sure that the application you installed while the value was changed is set to NOT install updates as they will likely require manual updates to this registry entry in order to actually apply the update. So the only time that you can actually make this change and have it work correctly is if you apply it immediately after installing the operating system and before you start installing anything else.
This article written by Stephen Chapman, Felgall Pty Ltd.