HELP! my sibelius is so slow!

Can anyone help? I have Sibelius, but it keeps lagging! When I click play (or press the spacebar), it stops responding for about 5 seconds, then bursts out playing about 5 bars into it. this si really annoying! Also, if I'm playing something fast, it skips some notes.

I use my Yamaha keyboard and connect it to my computer via MIDI to USB. I have Vista, 2 Gb of RAM and an AMD athlon 64 processor 3800+ 2.40GHz. Please can anyone tell me what is wrong and how can I fix it??

thanks

I have seen a case of this happening before, with almost the exact same circumstances as you, and I'm 90% sure the problem was Windows Vista itself.

If you are able, I would try the software out on XP to see if it runs faster. Personally I think Vista is a terrible piece of software anyway, and would uninstall it; but maybe the pros are greater than the cons for you.

Vista has a ton of graphics that can really slow your computer down sometimes. Turning them off might help your problem.

Start -> Control Panel -> System -> Advanced System Settings (in the bar on the left) -> the first Settings button (in the Performance frame)

Just uncheck everything.