By default Windows installs all the programs in the drive in which it is installed. In most cases it would be C:\Program Files.
You can always change the installation path for each program during its install. But if you install all your programs on a different drive, you might want to considering changing the default installation path.
To make it happen, open regedit and navigate to the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
Right click on the value named ProgramFilesDir & change the default value C:\Program Files to the path you want to install all your programs in.
Click OK > Exit.
Windows, by default, will now install your programs in the new drive or path.
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