The other day I installed SQL Server 2005, but I didn't used because I was preparing the PC formatted to work again. Just today I realized that the installation has not installed Management Studio, but I was sure to have asked setup to install it.

So I opened the setup again to verify the configuration, and really the Management Studio wasn't there. The Tools directory too was empty.

I then inserted the SQL Server disk into the DVD bay and asked for a reinstall, but I got strange error saying Management Studio was there. Where I really don't know.

So the solution is (and I didn't install SP2 yet, in order to rule out problems like different version)

1. Run the installer and ask to remove workstation components
2. Rename the tools folder in C:\Program Files\Microsoft SQL Server\90
3. Go to into the Microsoft SQL Server DVD (i.e. D:\ENGLISH\SQL2005\DEVELOPER\SQL Server x86\Tools) and run the setup.exe, select the component you need and proceed with the installation.