Issue:

When you start to install, you get error 1327, which references an invalid drive number. 

'Error 1327: Invalid Drive: U:/' and 'Fatal error during installation.

Causes:

The System Registry may be erroneously pointing to a temp drive.

Solution:

1. Back up your Registry.

2. Go to Start > Search > and then type Regedit.

3. Navigate to the following folder: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders

4. In the right panel, search for entries that list the drive letter referenced in the error message. 

5. Modify the value of those entries to to point to C:\ drive and verify that the folder path referenced in the key value exists.

6. Repeat the same steps for the following key: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders