Download Digsi 4 For Windows 7 ((link)) -

Many engineers still have the original DIGSI 4 discs. You can copy the contents to a USB drive and install on Windows 7. Ensure you have the license key (dongle) ready.

Siemens is the only authorized source for DIGSI 4. The software is proprietary and typically requires a license key to unlock its full functionality. download digsi 4 for windows 7