Windows uses the System Disk for installing any new applications, That is, if your Windows is installed on the C Drive, the default folder where all the applications you install would automatically show up as C:\Program Files , unless of course you change it manually while installing the application’s locations. If you almost always prefer to NOT install on the System Disk, but instead on another partition, say, the D drive, then rather then changing the default location every time, you can change it just once,.
To change the default location for installing application we will need to make a registry hack, for this we need to backup the registry before making any changes to it. To get into the registry, click on Start, then click on Run and type in regedit and press Enter.
To backup the registry, click File and then Export.
Now navigate it to the following location in the registry:
and look for a key titled ProgramFilesDir
Now double click on ProgramFilesDir key and change its Value data from C:\Program Files to D:\Program Files or any other drive of your choice, Click Ok then Exit. The default directory for installation of all you programs shall now be X:\Program Files [ X be the drive letter of your choice].