A pst cannot be utilised by more than a single instance of outlook at the
same time
There are methods of syncing two pst's, see www.slipstick.com for options
And if you are using / able to use an imap account, then it wont be
neccessary

"Chuck" wrote in message
...
I have Outlook 2003 installed on an XP machine. My new laptop is running
Vista and has Office 2007 installed although Outlook has not been
activated
there yet. The Vista machine has access to disks on the XP machine via a
wireless router.

I would like to activate Outlook 2007 with its own .pst file(s) and access
to the Outlook 2003 files. (I would use the laptop's Outlook 2007 .pst
file(s) when traveling and the XP machine's Outlook 2003 files when at
home.)
Is this possible? Could Outlook 2003 and 2007 run at the same time while
sharing the Outlook 2003 files? What pitfalls should I expect?