Which OS are you running rrufast?
Under vista, did you try right clicking on the install file and run as administrator?
The error code you are getting "1920", is that during install? If so it is the windows installer error, that means it's a generic service failed to start due to permissions error. (not much help with windows installer errors in general.)
After the install was done, did you even see the services created in the services.msc? (NeatReceipts Database Controller, and SQL Server (NR2007) )
What happens when you try to manually start those services? If it throws an error, check your event log for the corresponding entry and it might guide you a bit more.
A note on my system in case you want to try again. I run with UAC turned off, since I do a lot of work that requires elevated rights. Might try the install that way (which is supposed to be the same as 'run as administrator')
Good luck!
EDIT: 3 minutes off from formulating the message, lost another one to Ditech!
-Jonathan Hardison-