If you need to change the install directory of TPP once it has already been installed, maybe to another drive, follow the below instructions.
1. Make sure you have a backup of the DPAPI key which is used to encrypt some of the data in the database, this is very important as if we don't have this key you will lose all your data. You can use the following utility on the TPP server to backup the key Program files\Venafi\Platform\DPAPI_KeyUtility.exe keep it somewhere safe
2. Uninstall TPP from the server you need to change the install location on, this article will help you remove TPP completely https://support.venafi.com/hc/en-us/articles/215913017-How-to-Completely-uninstall-Venafi-in-preparation-for-new-install
3. Open up the registry and go to HKLM\Software\Venafi\Platform, if the key "Base Path" exists, delete it
4. Run the product installer and select different location for install files when prompted.