Hi can I get some help please

somehow I have interfered with QtWebKit4.dll
I can no longer open the Kindle App it is still in Programs etc but when I click on the Kindle Icon to open it I get this:
Error Unable to Locate Component
This application has failed to start because QtWebKit4.dll was not found
Re- Installing the application may fix this problem
If I Delete and Reinstall the Kindle for PC App will all my Amazon data for my Kindle DX: Reg, PID etc remain? Or will I have to re-register it all? Is there another way to reinstall just the file [I]QtWebKit4.dll Cheers Dasha