I bet it's MSXML6 as I've only got MSXML5 as downloaded via patches to my XP Pro setup. I've never pulled MSXML6.
Here's how to test for sure.
1. Find the directory containing MSXML6.dll 2. Open a command prompt and change into to this directory. 3. Issue the following command minus quotes "regsvr32 /u msxml6.dll" 4. Find the directory containing previous version such as MSXML5.dll or MSXML4.dll 5. Open a command prompt and change into to this directory. 6. Issue the following command minus quotes "regsvr32 msxml5.dll" 7. Try running the ProntoEdit software again and see if this works.
If you find that things still don't work, do the following to put your system back to previous state.
1. Find the directory containing MSXML6.dll 2. Open a command prompt and change into to this directory. 3. Issue the following command minus quotes "regsvr32 msxml6.dll"