Installation Win 7 Pro on VirtualBox 5.2.6 failed

[Tiktak]

Installation Win 7 Pro on VirtualBox 5.2.6 failed

First time installation yesterday was successful.
Uninstalled and reinstalled this morning, a message popped up saying:
"VirtualBox Error
Failed to open a session for the virtual machine Windows 7 Pro."
What is the problem?
How to solve it?

Thanks
Tiktak

[socratis]

What is the problem?

With the amount of information given, we can't say a lot. "Something failed". And? Now what?

You got to be more specific. What did you do? How can we replicate the error, you need to tell us the steps. Was this all that the error had to say, nothing more?

Uninstalled and reinstalled this morning

What? Your Host? Your Guest? Your VirtualBox? All of the above?

You need to be more specific. Host complete version, guest complete version, VirtualBox complete version, things that you did, things that you notice. Logs! We're not sitting in front of your computer, you are. And you got to describe the situation if full and complete details.

[Tiktak]

Thank you.
Sorry for the simplified post.

The host: Desktop PC, Windows 10 Home 64-bit.
The guest to be: Windows 7 Pro. 64-bit on disc.

Downloaded VB 5.2.4 about 4 weeks ago.
Installed it on my Windows 10, every step by default, a week ago but did not install the guest.

Put Windows 7 install-disc into my DVD drive.
Installed Windows 7 Pro 64-bit,every step by default except increasing memory to 4
G, on VB 5.2.4 as the guest on this past Sunday, and installed anti-virus app's. It ran smoothly.

Got a message saying a new version of VB 5.2.6 was available.
Downloaded VB 5.2.6.
Uninstalled VB 5.2.4.
And put my Windows 7 install-disc into my DVD drive.
Installed VB 5.2.6, every step by dafault, on this past Tuesday.
And tried to install Windows 7 for the guest at the same time.
Went throught neccessary setting, every step by default except for selecting USB 3 ,
Did every step the same as previous installation.
when "Normal Start" was tapped, the message popped up saying:
"VirtualBox-Error ? X
Failed to open a session for the virtual machine Windows 7 Pro.
Details
OK Copy "

Do not know what went wrong or how to solve the problem.
Help please.

Thanks.
Tiktak

[BillG]

Why were you trying to install Windows 7 again? Uninstalling VirtualBox does not uninstall the virtual machines. It should still be there. Did you look? Or are you trying to install Windows 7 again on the same vm (which still has Windows 7 installed)?