Which Operating System, Firewall, and Anti-Virus are you using?
For W7 and Vista you must set \holdem manager\holdemmanager.exe, hudfuncsapp.exe are started as administrator. Run the windows explorer and navigate to your Holdemmanager2 installation directory. Right click the executables and select properties... then select "Run as admin" from the compatibility tab.
Add exceptions to the windows firewall for those files even if the firewall is turned off. If you have a 3rd party firewall, do the equivalent or uninstall it temporarily.
Make sure your video card drivers and windows auto updates are fully updated. Make sure you have Microsoft .NET Framework 3.5 SP1 (or later for w7) installed.
Turn off User Account Control: How to Disable and Turn Off UAC in Windows 7 « My Digital Life
Update to: http://www.holdemmanager.com/Downloa...2.0.0.6233.exe
What are your computer's stats? CPU, RAM, harddisk, etc?