Welcome to LQ; VBox is a great idea for 1st-try Linux.
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Does your 'host' Win10 PC have 2-4+GB ram? (I hope it's
not this)
How much 'Vram' did you give your Mint guest?
Here's a very 'outside the box' idea to 'test' your Win10 VBox:
this 7MB! (or other)
.iso <-click to download guestOS
(96MB Vram ok;
no .vdi (Vhdd); Mint needs 1G+ram!)
Here's a VBox forum post that includes a link to *essential info*.
Let us know... Best wishes!!!