Ok, I have been trying to solve this problem for about 5 hours, and it frustrated the hell out of me for the longest time. I finally figured it out. Most of you guys probably know how to do this, but I haven't been able to find the proper solution to it posted in any forums when doing a google search, so I am doing one right now to get it over once and for all. This guide is to help myself a few months down the line when I will probably forget everything and my computer crashes, I have no means of retrieving how to do it. I also hope that it will serve some of you well.
Since Virtual Box is free open software compared with VMware, this might be the best solution for lots of people, but it's not as idiot proof as VMware. The version I will be referencing is 5.1.1 One of the main problems is the drag and drop file does not work upon new installation of Windows.
So what you need to do is click "Devices" on the top menus and go all the way down to Insert Guest Addition CD image. From there you will see under my computer a CD rom saying "Guest Addition CD image" or something like that.
Click on it and install the packages. Then restart the computer. That's it. I have no idea why it was so difficult for the internet to say this. Then of course you will go under Devices again and under Drag and Drop, Copy and Paste, select what you want, host to guest, bidirectional, whatevers.
For your USB devices to be recognized, you will have to install the extension pack.
You can find this here:
https://www.virtualbox.org/wiki/Downloads
You'll have to install this under the Administrator user account. Tried many times on a regular user account and for the life of me, will not install. After this, then you restart the virtual machine, also restart your regular computer.
Then voila, all should work. Virtual Box is actually a good alternative to VMware, and it's FREE!
Just my 2 cents. Hope this helps someone, but really it's just a guide for me in case I forget.
Cheers.