Virtual Box install hangs - appears to be conflict with VPN network driver

[bitbucket]

When trying to install Virtual Box on my Dell Win7 64-bit laptop, the install process got near the end and just hung. I checked Process Explorer and the hung thread call stack was the below.

ntoskrnl.exeKeWaitForMultipleObjects+0xc0a ntoskrnl.exeKeAcquireSpinLockAtDpcLevel+0x732 ntoskrnl.exeKeWaitForMultipleObjects+0x26a ntoskrnl.exeNtWaitForSingleObject+0x41f ntoskrnl.exeIoReportTargetDeviceChange+0xe6d ntoskrnl.exeKeSynchronizeExecution+0x3a23 wow64cpu.dllTurboDispatchJumpAddressEnd+0x6c0 wow64cpu.dllTurboDispatchJumpAddressEnd+0xf5 wow64.dll!Wow64SystemServiceEx+0x1ce wow64.dll!Wow64LdrpInitialize+0x429 ntdll.dllRtlUniform+0x6e6 ntdll.dllRtlCreateTagHeap+0xa7 ntdll.dllLdrInitializeThunk+0xe ntdll.dllZwWaitForMultipleObjects+0x15 kernel32.dllWaitForMultipleObjectsEx+0x8e msi.dll!MsiEnumProductsW+0x2bf0 msi.dll!MsiReinstallFeatureW+0x2a4 msi.dll!MsiInstallProductA+0xcc VirtualBox-4.2.4-81684-Win.exe+0x1fcf VirtualBox-4.2.4-81684-Win.exe+0x27f4 kernel32.dllBaseThreadInitThunk+0x12 ntdll.dllRtlInitializeExceptionChain+0x63 ntdll.dllRtlInitializeExceptionChain+0x36

I killed the installer and rebooted. I checked device manager and noticed my VPN client network adapter in the list, "NCP Secure Client Virtual NDIS6 Adapter". This is the adapter created by my VPN client.

I tried disabling that adapter in device manager and rebooted. After the reboot I tried again to install Virtual Box and this time it worked without hanging. After installing, I re-enabled the VPN network adapter and rebooted again and all appears to be working now.

[bitbucket]

ok, the call stack didn't come through right above. Here it is again.

ntoskrnl.exe!KeWaitForMultipleObjects+0xc0a
ntoskrnl.exe!KeAcquireSpinLockAtDpcLevel+0x732
ntoskrnl.exe!KeWaitForMultipleObjects+0x26a
ntoskrnl.exe!NtWaitForSingleObject+0x41f
ntoskrnl.exe!IoReportTargetDeviceChange+0xe6d
ntoskrnl.exe!KeSynchronizeExecution+0x3a23
wow64cpu.dll!TurboDispatchJumpAddressEnd+0x6c0
wow64cpu.dll!TurboDispatchJumpAddressEnd+0xf5
wow64.dll!Wow64SystemServiceEx+0x1ce
wow64.dll!Wow64LdrpInitialize+0x429
ntdll.dll!RtlUniform+0x6e6
ntdll.dll!RtlCreateTagHeap+0xa7
ntdll.dll!LdrInitializeThunk+0xe
ntdll.dll!ZwWaitForMultipleObjects+0x15
kernel32.dll!WaitForMultipleObjectsEx+0x8e
msi.dll!MsiEnumProductsW+0x2bf0
msi.dll!MsiReinstallFeatureW+0x2a4
msi.dll!MsiInstallProductA+0xcc
VirtualBox-4.2.4-81684-Win.exe+0x1fcf
VirtualBox-4.2.4-81684-Win.exe+0x27f4
kernel32.dll!BaseThreadInitThunk+0x12
ntdll.dll!RtlInitializeExceptionChain+0x63
ntdll.dll!RtlInitializeExceptionChain+0x36

[aeichner]

Please reopen if still relevant with a recent VirtualBox release.