Any files on your iPAQ will remain on your iPAQ and can be synced with your new computer without issue. In addition, there is no need to purchase Outlook unless you want to use Outlook.
All you need to do is download/install Windows Mobile Device Center (freeware), which is the Windows Vista/7 equivalent of ActiveSync for Windows XP. Once installed, connect your iPAQ and sync your files, contacts, etc. with your new computer as desired.
Hope this helps,
Moving iPAQ 111 to Windows 7 from XP
I just purchased an HP Pavilion computer with Windows 7. I want to move my iPAQ classic 111 from my current Toshiba satellite computer running XP to my new HP computer. What do I need to do? So far it appears that I need to purchase Microsoft Outlook for Windows 7. Is this true? After I have installed Outlook on my new computer what should I do? Needless to say I want to keep my current iPAQ files including my contacts.