If you are talking about synchronising your information on a regular basis
between the two computers, I cannot help you.
If you want to copy your .pst to look at it while traveling, you should be
able to do so. You indicate you got a permissions error.
I'm guessing that the two computers are not members of a domain, in which
case you are really logging on as two seperate users, regardless of whether
you are using the same username/password. You state that you are the
administrator on both computers. I suggest that you open the properties for
the .pst on the desktop computer, click the security tab, then click the
advanced button.
You should see a line that says something like Administrators
(NAME\Administrators) and says Permission Full Control, likely inherited from
something.
If all this looks like I am describing, click the Cancel button to exit
these screens to avoid making any changes. Copy the file to the laptop.
Logged onto the laptop as an administrator, open the file properties, click
the security tab, and click the Add button. From here you should be able to
type the logon name of the laptop account you want to have access, click
check names, then allow that logon to read & execute.
For your own sanity, I suggest you create an outlook profile without regard
for this new file, and after outlook is opened, go to File > Open > outlook
data file> and point to your .pst.
It should show up as a different tree of information that you can browse at
will.