我把我在piazza讨论组里面发的问题和解决方法直接拿过来了，所以是英语的
"vagrant up" failed to boot the virtual machine
win7 64bit
VirtualBox-4.3.28-100309-Win
vagrant_1.7.2
After typing "vagrant up" in cmd, it comes to this, and the virtual machine "sparkvm" is always "Powered Off", I don't know what's going on. Could someone please give me some help?
解决方法：
Well, it turns out that the problem is about "uxtheme.dll" file, I just downloaded an original uxtheme.dll and replaced the c:windowssystem32uxtheme.dll, then the problem was solved.