Hello there, Paul!
First, are you sure there is no real error in the path you are describing? It should have slash after a colon “c:[u][/u]documents\bbworkspace”.
Second, can you try right click the installer, and select “Run as administrator” to force set the administrator rights to the process.
Third, if all else fails, you can try to download an already installed version from here - http://mybeatbuddy.com/forum/viewtopic.php?f=16&t=443&p=1818#p1776. Further instruction there as well - http://mybeatbuddy.com/forum/viewtopic.php?f=16&t=443&p=1818#p1818. Be sure to download and unpack it to correct place, then run a .reg file.
Note, that the third option is not an official option to use the software. It is provided only as a workaround, if first two steps didn’t solve your problem.