virtualbox.org

I have a fresh install of Vbox V5.2 running on Mint 18.2 host at 3.49ghz 8 core CPU with two CPUs and 4gb RAM assigned to session. 3d and 2d turned on with 256mb and guest additions installed in a Win 10 Pro 64b guest. It is running to slow to be useable.

Yup, Win10 uses a lot of CPU and I/O especially on a fresh install, what with Updates, Cortana and Defender all thrashing the disk at once. I wouldn't even bother unless you have loads of CPU to spare.

If you want to continue this then provide a VM log file. With the VM fully shut down, right click it in the GUI. Select "Show Log" and save "VBox.log" (ONLY) to a zip file. Attach the zip here.

I don't use Cortana and don't really need Defender, so, when (and if) it finishes with Updates, I'll check services.msc and see what I can turn off. I don't intend to use the VM (I have Win 7 and XP vdi's) very often, so running a malwarebytes check once in a while, should make Defender un-necessary.

Win10 doesn't really let you uninstall Cortana or Defender. But you can reduce the overhead of the former and prevent it from trying to search online. As to Defender, you can disable it for short periods if you need to get some work done. Once it's done its initial scan the overhead will be much less.

That's one of the things I hate about Windows. Typically I only want to use it to test something and it is a PITA to have to wait while it does what it wants to do rather than letting me do what I want while it waits till I'M DONE!!!!

I'm pretty sure all the other consumer level host OS's are the same, e.g. OS X, Google. They design the OS for the lowest common denominator. It's understandable if irritating at times.

lewmur wrote: with two CPUs and 4gb RAM assigned to session.

Why so tight with those cores?

According to stuff I found on Microsoft's site:

Windows 10 supports a maximum of two physical CPUs, but the number of logical processors or cores varies based on the processor architecture. A maximum of 32 cores is supported in 32-bit versions
of Windows 10, whereas up to 256 cores are supported in the 64-bit version.

The underlying OS will get its share of those cores. There is no reason to specify only so many cores for your virtual machines. Giving the VM more cores does not deprive the host of cores.

The Virtualbox manual says this about Cores:

On the “Processor” tab, you can set how many virtual CPU cores the guest operating systems
should see. Starting with version 3.0, VirtualBox supports symmetrical multiprocessing (SMP)
and can present up to 32 virtual CPU cores to each virtual machine.
You should not, however, configure virtual machines to use more CPU cores than you have
available physically (real cores, not hyperthreads).

So try giving the OS more cores. See if that makes a difference,