Richard,
By default, your Creative Cloud apps are installed in the Program Files folder (Windows) or the Applications folder (Mac OS). You can change the default install location at installation time if you choose to, but it is not generally recommended. To do so, open the Adobe Creative Cloud desktop app and click the gear icon at the top right of the window. Choose Preferences > Apps > Install location > Change. Navigate to the desired location and click Open. Your new install location will appear in the menu.
Note: The shared resources and temporary files will still be stored on your primary drive. If a lack of disk space is preventing installation then please verify you have sufficient space on the primary drive for the temp files and extracted installation files to be placed.
Pattie
moving from Adobe Creative Cloud to Creative Cloud Download & Install