Make sure the tools are supported in your Excel and Windows versions. If you are running Windows 10, a repair install will fix the problem. Log onto Windows as a full administrator. Re-run the installer When prompted for Modify or Repair select Repair. Textbook users: If you have a 8.x textbook version Log into the Lumivero Community and click the Submit a Case button. Provide your textbook name, and ask for the latest DTSuite8-Setup.exe. Download that installer to your desktop Right-click it and select Run as administrator. If you're prompted for Modify or Repair, select Repair. If you see a Customer Information screen during install, change "15-day trial" to "I am upgrading or reinstalling" If you have a 7.x textbook version, uninstall it in Control Panel, then do a fresh download. You will need your textbook to answer the challenge question. You'll get the 8.x textbook version automatically.