id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host 9913,Windows XP Guest application causes hang of VirtualBox Guest & Windows 7 Host,starfire,,"I am running Virtualbox 4.0.10 successfully with a Window 7 host and a Windows XP guest. Any version of Virutalbox newer than the above suffers the following issue: When starting an application on the guest called ""Cisco IP Communicator v7.0.5.4"" the guest hangs and does not respond and also the Virtualbox.exe process running on the host hits a constant 25% of CPU (which is one full CPU as I have a quad core system) and cannot be terminated via windows task manager, also of course Virtualbox GUI on the host also fails to respond - the only way to recover from this situation is to reboot the host. I have tried things like trying a different networking adapter rather than PCnet FAST III, disabling the VTx, nested paging options, switching back to 1 CPU for the guest but it always causes this hang. Attached are logs from a successful run of the guest on 4.0.10 obviously as it hangs I cannot attach from when a newer version suffers the hang. I have held off logging a bug until now as I was hoping newer versions may resolve the issue but the fault is still present.",defect,new,other,VirtualBox 4.1.6,,,,Windows,Windows