Using Gnucash on two computers

[oldcourt at talktalk.net]

Dear Sir/Madam

I have set up gnucash 2.27 on my computer at home and modified it to produce accounts  for the play school I write this email from. I have set up the same version of Gnucash on the school's computer but cannot input and change data from one to the other. It would help us immensely if data could be added to and transferred from both computers, but when I try to import .xac or log files I can import but they will not save.What am I doing wrong ??
I would be grateful for any help you can give as a lot of information has been added and the program seems just what we need.
Both computers are using Windows XP with all updates added.

Regards

Tony Cole