Below is the procedure to change the default WINDOWS installation folder C:WINDOWS to C:WINNT.
1. Install the OS with default installation folder (you don’t be given any option to change at the first time).
2. Again boot to the installation CD.
3. select installation of OS (not repairing OS).
4. select the existing C:WINDOWS partition.
5. select leave existing file system intact.
6. select different folder for installation (not to delete the files under current directory and copying the files which just re-install the OS in C:WINDOWS)
7.Type WINNT.
Note: The default OS installation time takes 39 minutes