I have an application that will only run on Windows XP and it utilizes a SQL backend server. I am putting new workstations in this office with Windows 7 and installing the software in a Virtual XP machine. However, the performance on my application is slow and users have had several problems with the app. For instance, one person needs to reconcile a checking account with several thousand checks monthly. With her 6 year old XP machine this worked fine. But with the virtual XP on a brand new i5 based system, she gets lockups if she selects more than 200 checks at a time and it is generally slower. There are other users who get errors that seem to indicate problems with the networking between the VM and the SQL. The old machines work fine when put back in place. Why the network problems with VM?
More info, I do have antivirus installed on both the host and on the virtual PC. I also have windows firewalls installed on both. These are machines on a Windows SBS 2003 domain and the SQL server is older. On the VM setup i have the network card set for the network card on the host machine. NAT is not enabled. Also have VM RAM set to 1024.