virtualbox.org

I am using kali linux,but when i try to install win7 on my kali linux.
If I logged in as root,everything is okay,it has sound and i can use USB easily.
But when i was using a non-root user,if i don't use sudo to start virtualbox,i can't use USB from the host.But if i use sudo,i can use USB from the host,but i can't hear any sound,and i can't input any sound too.
How can i fix it?

Re USB usage, each user account has to be part of the 'vboxusers' group. From the manual https://www.virtualbox.org/manual/ch03.html#usb-support:

On supported Linux hosts, Oracle VM VirtualBox accesses USB devices through special files in the file system. When Oracle VM VirtualBox is installed, these are made available to all users in the vboxusers system group. In order to be able to access USB from guest systems, make sure that you are a member of this group.

I have no idea about the sound problem, though.