Thanks, jazzmammal, I'm well aware that my laptop was part of the navigational system from the Ark, but I've treated it to an external 500 GB hard-drive to beef up its capacity, and allow me to dual-boot Ubuntu. The improvement in the performance of the laptop (and a marginally younger desktop) with the switch in OS was dramatic!

After a year and a half with Ubuntu, I use Windows very rarely now, but I have to use it for BIAB and for iTunes. (Actually, I can run BIAB 2010-5 with Wine under Ubuntu for editing charts and MIDI playback, but not RealTracks; haven't tried 2012 yet).

I play guitar, I don't use my laptop in a live or rehearsal context now, I use MusicReader on my iPad for charts, many of which have been prepared on BIAB. My clarinet-playing colleague uses BIAB for practice at home, and has a subset of our repertoire ready to go in BIAB so that we can go out without our keyboard-player if we have to. I'd like to keep my laptop in step with his as far as RealTracks and charts are concerned to provide a backup in case his laptop breaks down or is stolen.

So you'll appreciate my reluctance to invest in a new laptop if the old one can be pressed into service!

But, it seems to me that the problems I'm having are problems of logic, not of speed or capacity, and that buying new hardware wouldn't solve them. Reinstallation of Windows might be a good plan, though.