Have used Virtual PC w/ XP Pro since obtaining my PowerBook last June. Use it to sync my Treo with Lotus Notes, since there is no Mac synchronizing app even thought the Mac Lotus Notes client works really well (for Lotus Notes). During the past 3-4 weeks, without warning and with no traceable causal event (hard drive problem, upgrade, etc.) XP has disappeared, twice. I open VPC and it wants to take me through the installation and setup again. Can't find XP on the hard drive anywhere (although perhaps I don't know where to look). Thankfully, there is nothing critically important in the VPC partition, but reloading, reconfiguring and resynching takes about an hour and a half. Any ideas about what might be causing the problems? Thanks.