You can often find the "Dell Systems Service and Diagnostics Tools" or "Service and Diagnostics" ISOs which replaced the older tech CD. Service and Diagnostics ISO v5.2.0 . Systems Service and Diagnostics Tools ISO v7.0 .
If you are working on a Dell system made after 2010, you likely do not need the DSTCD. Modern alternatives are more efficient and safer to use: Dell CD ISO - Service and Diagnostics, v.5.2.0, A00 dstcd (dell service tech cd) download
Finding an official, modern download for the specific "DSTCD" name is difficult because Dell has transitioned these tools into newer packages. However, you can find the equivalent utilities through these official channels: You can often find the "Dell Systems Service
