Siemens does not currently support running Step 7 on Windows 7. There are unsupported ways of getting Step 7 to install on Windows 7 that can be found on the internet, but I would highly recommend against trying these. If you have to run Windows 7 as your operating system I recommend using a Windows XP Pro Virtual Machine for Step 7.

Siemens also has a OS compatibility chart for Step 7.

Siemens indicates that Step 7 is not compatible wiith Windows 7. Do you have the ability to run Step 7 in a virtual machine? We have done this even with Windows XP and VMware server or Player. It works well as long as you do not assign too much RAM from the host and you do not need a PCCARD The VM will not connect to teh PCCARD but work fine with a USB or Ethernet connection.