I had this issue of the "Pronto Data Service" not starting after I moved to W7 from XP.
I was also getting messages in the event log about "System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt."

I resolved this by changing the account used by the service.

- Run services.msc
- Double-Click Pronto Data Server
- Select Log On tab
- Change from Local System Account to "This Account" and use your normal sign in details.

The service now starts fine.

When sending a new config to the I still get a C-11 Unable to communicate with device after the download progress pauses at 100%, but the device/config seems to work ok anyway.