I installed on a Windows 7 Professional 64 bit system the virtual box (6.1.16) + extension pack. Neither a normal start or a start without GUI works. Everytime the same error appears (attached) since a few days. Windows XP 32 bit is the guest system.
I already used "sfc /scannow" which found some corrupted files but it couldn't repair them.
I have already reinstalled VB and also disabled the AV (however VB was already working with the AV without any problems) and also checked the Diagnosing VirtualBox Hardening Issues.
Am I perhaps missing something in the log files that could help clarify the problem?
Sadly there is no error message showing with "Thread not alone" or "More than one thread in process" and I already run sfc /scannow multiple times.
Unfortunately I can't figure out myself from the log if a dll is missing or something else is causing the problem and hope one of you can.
On the other hand you do have third party AV installed (Symantec), and you make no mention of what testing you did to eliminate that potential problem.
Also, note that Windows 7 hosts are themselves becoming a rarity, so we don't really have a lot to compare your performance against. Plus they are no longer officially supported hosts in VirtualBox 6.1.x.
It depends on if the other host systems have hardening troubles too. It all depends on what extra stuff is installed.
As an example, I have never had hardening problems on my two Windows 10 and one Windows 7 hosts. But I don't install extra antivirus or HP ProtectNanny or other software. I just use Windows' built-in AV on the 10 hosts, and I don't browse the internet on the old 7 host.
You can test the other hosts by trying a Linux VM with Ubuntu. If you can start the Linux LiveCD in the VM, then you don't have show-stopping hardening problems.
I solved the problem by downgrading to VB 4.0. I know I no clean and safe solution but at least now everything works again . So this thread can be closed.
That's actually not a 'solve', it's just running a Virtualbox version that didn't have hardening checks.
Hardening was inserted to plug a security hole enabled by Windows' DLL injection capabilities, where malware that got on the host PC could get greater privileges to wreak havoc through Virtualbox. Hardening works to plug that security hole. Running without Virtualbox hardening is like running without antivirus. You have to really be on top of your game when using an internet-connected PC without A/V. And websites you normally use safely can get infected themselves, and get malware onto your PC. Same caution for running Virtualbox without hardening on an internet-connected PC.
Additionally, 4.0.x is rrreeeaaalllllyyyy old and modern OS's may not run on it. The last version of Virtualbox that did not have hardening is 4.3.12, and Windows 10 would not run on it as a VM.
If you can get another disk for your PC I suggest switching disks and reinstall the PC's OS. Then install Virtualbox. Your VMs should run fine. Then install other programs one at a time, rebooting each time and running Virtualbox. Once you find that Virtualbox throws the hardening error, the last program installed should be the problem. Sometimes a complete reinstall allows everything to coexist. And your PC should perform better.
Yes, you are right, I am doing this for a man who is older than 60, as soon as an icon looks different he can't handle it anymore. He is currently just happy that the system works again. Still, the next step will and must be a new and more secure computer. Thank you all for your advice.
. So this thread can be closed.