Missing software and file drivers is often a leading cause of DEF file problems. It is highly recommended that you scan your PC using the DEF File Repair Tool. It will analyze your files and make sure you have the necessary file openers.
DEF file error symptoms can include the inability to open DEF files, program lock-ups, crashes, slow PC performance, startup and shut down problems, and installation errors.
Fixing the Problem
To ensure DEF files can be opened and read by your computer, download and run the DEF File Repair Tool. Simply click the button below to download the software.