virtualbox.org

Hello! I have used at least 3 versions of VirtualBox and every version is so so laggy.
First things first, for example, I can install Windows 7 x64 on VirtualBox, it works, no problems, but it is so laggy. The problem? Well, I can only select 1 CPU in settings. Why? If I select more than 1CPU (For example 4CPUs) it becomes way laggier, it doesn't even boot, I see those 4 dots that are suposed to make the Windows 7 Logo on boot, but it takes too long to boot, i let it for like 5 minutes and it was still loading. On 1CPU selected it boots(it's installed on my SSD because on HDD it would've take too long to install it), but tasking is so laggy in windows using 1CPU. I wanna use more than 1 CPU, but as I said, if I choose more than 1 CPU it will take a whole day to boot. I don't know why honestly...

CPU: i5 10400F
GPU: RTX 2060
RAM:16GB (at least 8190MB allocated to Virtual Machine!)
SSD: 500GB
OS:Win 10 Pro ver 1909 (everything above 1909 is bad!)

Please help me make it work because I wanna use VirtualBox. I used other Virtual Machine and it works just fine if I select 6CPUs, but I wanna use VirtualBox.

If you give VirtualBox more work to do (e.g. manage extra cores that aren't being used) then of course it will get slower. A VM can't simply ignore the unnecessary cores like a physical PC does.

Further discussion will require a zipped VM log. Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

Do you mean like this?
Btw, that's not the problem, I can't even use 2 Cores or 4 even tho my CPU has 6 psysical and 12 threads...
Even when i tried to install MacOS on VirtualBox I had the same problem, with 1 core it worked but it was laggy, but with more than 1 core it wouldn't boot...

Try this: allocate 2 cores (which btw should be your default). No more or less. Then set the hypervisor API to "Hyper-v" (I believe you already have this).

I would also like to see an example where you are actually running the guest OS from the hard disk, and not the (whatever the installer is using) that's on the install DVD.

Another thought occurs: what is drive D: ?