Cheers for the info, I'll give things another go. Uninstalled the program and get an error message towards the end of the re-install:
C:\Program Files\Cakewalk\Shared Utilities\Null Proxy.dll
Unable to register the DLL/OCX:RegSvr32 failed with exit code 0xC0000005
Probably had this the first time round and just ignored it - but this is supposed to be an Admin issue but I started the installer using 'Run As Administrator'. I see there are a couple of other threads of people who have had this problem who haven't had a fix supplied.
I have an Alienware laptop with two hard disks - the C: drive is a flash disk with the Windows 7 partition on it and the other drive is a 500G with data - this has a couple of partitions on it where there is one for the music. 8G of memory and i7-3630QM processor.