I have installed Siebel on Windows7 64 bit this week.
1. Download the 64 bit Siebel media files from eDelivery.oracle.com
2. Download the image creator.
3. Ensure that the zip file are not corrupted. There is a utility that allows you to test that.
4. Unzip all the media files in C:\Siebel_Install_Image folder.
5. Unzip the image creator also in the same folder.
6. Run the Windows Image Creator exe file. (Ensure that you have the latest version of java). Select all the installation files that you want to create. (Tools, Client, Sample DB)
7. If the java version does not work, please run the utility from command prompt in console mode . (Command Windows_ImageCreator.exe -is:javaconsole -console)
8. You will find the all the installation files created in a C:\Siebel_Install_Image\184.108.40.206 (or chosen other version)