One of our satellite companies is testing the Zimbra Desktop in preparation for first steps to migrate from MS 2008R2 Servers to Unbuntu and the Zimbra system. We have installed Zimbra Desktop on a Win 8 x64 machine. The program has been running flawlessly with approx. 40 email accounts (GMail and some MailEnable). No changes have been made to PC OS however, when attempting to open the Zimbra Desktop, the GUI window merely sits there with the word "Loading" and never actually opens. We have attempted to reload the Desktop software in "Repair" mode and this did not resolve the issue. We would like to continue testing this product. If the application cannot be opened, how do we preserve the data of the thousands of email contained in within the program's database? Any help or clue as to what the problem may be and a resolution would be greatly appreciated.