Make sure that DSS.exe is located on your Desktop.
Click on your START button, then choose Run. A little box will appear.
Now copy and paste all the following in bold (including the "" marks) into the run box and click OK.
"%userprofile%\desktop\dss.exe" /daft
This will start DSS in a different way. A small window will appear.
Click on the Scan button.
If it finds faulty file associations, they will appear in red beside a checkbox. If this occurs, just place a tick in the boxes in question.
Click the Fix button.
Re-scan and save a logfile. By default, it will save as daft.txt.