Finally I found it... After couple of days trying to install Visual
Studio .NET 2003 and having the same problem of hanging at 60% of the
Generating Setup Script, this is what i did:
1. open your Window Task Manager (Ctrl-Alt-Del)
2. Select the Proccesses Tab
3. Sort by Image Name
4. When the installation starts a new task called "msiexec.exe" is
created.
5. Select that task
6. When the setup reaches the part of "Generating Setup Script" and
the progress bar reaches around 60%, usually the part where it hangs,
you will notice that another task named "msiexec.exe" is created. End
the new process (the one that has lower Mem Usage). and this should
allow the installation to proceed.
Should the intallation hang again, do the same thing...
Good Luck
Sumber : http://www.developmentnow.com/g/58_2003_11_0_0_292633/Found-it---NET-Setup-hangs-on-Generating-setup-script.htm