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.DEF Support Guide
How To Open DEF Files
Causes of .DEF File Errors
Registry errors are often the leading cause of DEF file issues. It is highly recommended that you scan your PC using the DEF File Repair Tool. This will perform a full system analysis and fix the problematic registry entries causing this issue.
Common Symptoms
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.
Download DEF File Repair Tool Download DEF File Repair Tool  (4.1 MB)
*File size: 4.1MB, Download time: <1min (Cable/DSL)
How To Open DEF Files
File:   .DEF
Instructions
STEP 1:
Download & run RegClean Pro.

STEP 2:
Click 'Scan' to search for errors.

STEP 3:
Click 'Fix All' and you're done!

Fix Your Computer Now

Designed for Windows 8, 7, Vista & XP
  7 Comments on "How to Open .DEF Files"

Flyguy says: Topic: Support
Thanks, it worked!

termin8 says: Topic: Support
amazing, a DEF file fix that works

JILLIAN says: Topic: Support
wow! the scan picked up lots of errors

DaBossman says: Topic: Support
Dude, you don't know how many things I tried to fix this until I found this.

Cat_Lover says: Topic: Support
I'm so happy. My computer works GREAT now!\!!

AstrosFan says: Topic: Support
I'm so happy. My computer works GREAT now!\!!

Rustang says: Topic: Support
now I don't need to buy a new computer LOL

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