If you are using Windows Vista as the file server check the following Microsoft KB Article which describes a problem with the maximum number of SMB connections to the server.
http://support.microsoft.com/kb/937082/en-us
Sage's official line is that only Sage version 2007 onwards are compatible with Windows Vista.
You must ensure that you don't install to the default location of Program Files since Vista doesn't allow files in this location to be updated.
If you are having problems installing or running make sure you run the Install and actual program "As Administrator". (Right Click on the Items to select this option). We have successfully installed Sage Version 13, 12 and Version 11.1 on Vista using the above method and it appears to work but you are obviously on your own in terms of Sage support if anything goes wrong.
To install Sage in a location other than the default, choose the Custom Install option in the Sage setup.
There appears to be a problem with Sage versions prior to 2008 with displaying Customer and Supplier Accounts. When an account is selected from the List displayed in the Customer or Supplier module the details are blank.
The workaround for this is to select the account from the drop down list on the Details Tab. The Account information is then displayed.