I have a late 2011 MBP 13" i5 with a 1TB Hybrid drive and the stock 4GB of Ram (16GB upgrade in the mail currently) and I have tried to run Windows 10 in Virtual Box but every time I try and run it, it cripples my Mac to the point it freezes up solid and I have to do a force restart the computer. I originally upgraded the Windows 7 virtual machine I already had been running. The Windows 7 machine ran ok but it still bogged down my Mac and I couldn't jump back and forth easily from the Windows 7 machine to OS X doing multiple tasks between the two. If I was going to run the Windows 7 machine, I needed to stick with it until I was finished with my tasks and then shut it down before moving back to OS X. Windows 10 doesn't even afford me that luxury. I tried doing a fresh install on a new Virtual Machine of Windows 10 from a Windows 10 .ios file and as soon as I created the machine and booted it to start the installation process, it froze the computer at the very first option screen past the opening Windows logo. Is the i5 in my machine just not powerful enough to run this anymore or is the RAM what is crippling me here?