Official support for Prolink 1.15 has largely been phased out in favor of newer suites, but it can still be found on trusted software archival sites and community forums: UpdateStar: This site lists ProLINK 1.15
If you have trouble running Prolink on newer versions of Windows, Sokkia released Spectrum Link (currently v8.2) as its official successor. It is also and offers more robust features: Enhanced Compatibility: free download drivers sokkia prolink 1.15.rar
While "Sokkia Prolink" is an older legacy program, it remains widely used for its simplicity and small file size (approx. 3.5MB). Below is a guide on where to find the software and its modern alternatives. Where to Download Sokkia Prolink 1.15 Official support for Prolink 1