Product:
Cognos Analytics 11.0.7
kit_version=11.0.7.17082211
kit_name=IBM Cognos Analytics
Microsoft Windows 2008 R2 server

Problem:
Error message when try to install to C drive. This happens in the beginning of the installation when you try to select where to install the Cognos software. The C drive is hidden by a Group Policy. You can in file explorer enter C:\ to view the drive and the files, but this is not good enough for the Install software.

Error message:
Install Location
The specified drive in c:\program files\ibm\cognos\analytics is invalid. Please specify a valid drive.

Possible solution:
Ask your IT department for Windows support to turn of the Group Policy that prevent the user from seeing the C drive.
The Install Anywhere program need to see the drive to allow that you select it in the installation dialog.

You can check the registry on the Windows server to see if there is a policy making this issue.
Start REGEDIT by type that on the START-RUN line.
Go to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
“nodrives”=Dword
If there is a NoDrives=4, then there is a policy for the logged in users to not see the C drive.
Right click on key Explorer and select “export” to get a backup of that registry part. Save to a file.
Change the value to 0 for NoDrives.
Exit Regedit.
Log out of Windows server.
Log in as the same user again.
Then you may be able to see the C drive direct, and the installation will work.

Otherwise you have to install it to a different drive (e.g. D:).

The value you can set at nodrives is a 26 Bit mask
A: 1
B: 2
C: 4
D: 8
E: 16
F: 32
G: 64
H: 128
add the numbers up to hide more than one drive.
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
“nodrives”=Dword