Don't even try to use the install script: it will not work. Vista's security mechanisms prevent the script from doing anythig on your VS 2005 install directories. I just went through this situation this morning and realized there was just one way to go about it: manually.
It's not that difficult, but took some time to reverse-engineer what the script was doing. The first thing you need to do is to locate the VS application wizards directory. In my case it's in:
C:\Program Files\Microsoft Visual Studio 8\VC\vcprojects
Under this directory you must create a new one named WTL (what else?). Now go to the directory where you installed the WTL 7.5 files and copy the following files:
to the vcprojects directory. You will need administrator clearance to do this. Now change the security settings of WTLAppWiz.vsz to allow editing. Change it so it looks like this:
Param="WIZARD_NAME = WTLAppWiz"
Param="WIZARD_VERSION = 8.0"
Param="ABSOLUTE_PATH = D:\src\WTL75\AppWiz\Files"
Param="FALLBACK_LCID = 1033"
Replace the D: path with your own WTL 7.5 directory. Finally, copy the WTLAppWiz.vsdir file to the WTL directory you created before and, going through the same security checks you did for the vsz file, change it so it reads:
..\WTLAppWiz.vsz ATL/WTL Application Wizard1An application that uses the Windows Template Library. 67774096#1154
You are done.