Do you mean that this happened right after installing it? If so, something probably went wrong during the installation, so please try reinstalling:
1. Restart your computer, to get a fresh clean system. (very important)
2. Uninstall PokerOffice via the uninstaller accessed via the Start button->Programs->PokerOffice in Windows.
3. Restart the computer again
4. Use the file browser to look for the folder where you installed PokerOffice. Typically c:/program files/PokerOffice. If it is still there remove the complete folder manually.
5. Download and install
http://www.pokeroffice.com/PokerOffice2.exe
6. Start PO and try again