(1. If your VC is installed on the C drive, please copy the file VC6LineNumberAddin.dll to the following directory:
C:\ProgramFiles\MicrosoftVisualStudio\Common\MSDev98\AddIns
2. Register
Double-click VC6LineNumberAddin.reg to register.
3. Enable
Open vc6, menu bar: Tools-gt; customize-gt; Add-insandMacroFiles
Check VC6LineNumberDeveloperStudioAdd-in
VC display line number _VC6LineNumberAddin\VC6LineNumberAddin.dll
VC display line number _VC6LineNumberAddin\VC6LineNumberAddin.reg
VC display line number_VC6LineNumberAddin\vc display line number description.txt)