The information in this article applies to:

• SONAR 4
• SONAR 3
• SONAR 2 
• SONAR 1
• SONAR LE
• SONAR  Home Studio Version 4

How do I fix an error in SEQUENCER.DLL when starting SONAR?Something interfered with your SONAR installation. Try reinstalling SONAR but click NO anytime you're asked to restart the computer during the install process. You WILL need to restart after the installation has been completed. 

If that doesn't fix the problem try this: Close all programs running in the background. Install DirectX 8.0a from Microsoft, then restart the PC. Next, reinstall SONAR. Do not restart the PC until the SONAR install has completed.

Lastly, please try the following:

a) Completely un-install SONAR from your computer. This is normally done from Start | Programs | Cakewalk. This will not remove any of your files or audio data.

b) Make sure nothing else is running while reinstalling SONAR in step 'e'. In Win XP/Vista, choose Start | Run and type MSCONFIG. Click OK, then click on the Startup tab at the upper right of the window that opens. Uncheck all items listed, click OK, then restart your computer. You can always recheck those items again at a later time.

c) Click the Windows Start button and select Run. At the prompt type REGEDIT and click OK.
Backup your Registry before making edits - you do this by clicking the Registry menu, Export Registry File.
Now delete the following Registry keys
        HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR 
        HKEY_LOCAL_MACHINE\Software\Cakewalk Music Software\SONAR 

Please note that this will remove any effects presets and key bindings you may have made in Cakewalk. You can back up those registry keys separately if you like.

d) Delete the files AUD.INI and TTSSEQ.INI from the Cakewalk program folder.

e) Restart your computer, then reinstall SONAR.

This should eliminate any software irregularities that are causing your problem, but let us know if it does not.