well my specs are AMD Athlon 64 X2 Dual core 5200+ 2gb of ddr2 ram but i may upgrade to 4gb for crysisnvidia geforce 8800gtx Soundblaster audigy 4 pro 24 bit audio HD and i own the yamaha motif ES8 workstation keyboard and its connected via usb for midi! oh yeah, does the vienna software support USB MIDI?
Yes, a USB keyboard is no problem. Under normal circumstances I would say get more RAM, but as Sibelius is unable to address more than 2GB (without making it LAA; do a search for Laa-Ti-Doh) it might be a waste of money.
DG