Greetings!
The below link will take you to the Acesonic KM 112 page. There you will find a link (about the middle of the page) to download drivers for Win 7 or XP 32bit. I have downloaded and looked at the files and notice that Vista is covered also. Some Vista drivers work with Win 7 also. Several of the program file names end with "64". I find that to usually mean a 64 bit driver. I would say that if you down load and install, the 64 bit drivers will be on your machine.
http://www.acesonic.com/mixersitem.php?id=1
I have read the users manual for your mixer trying to figure out the microphone delay you reported.
The installation of the above drivers may or may not correct that.
An excerpt from the manual reveals:
There is a front panel switch (see page, “Front Panel Operation and Functions,” item number 9) to choose whether the KM-112 will function as an Audio device (mixer) and work with the audio in signals (see rear panel information above), or work as a computer interface,
allowing you to record your vocals through the USB connection to your Windows computer.
With the above in mind, it appears that the USB connection was intended for recording purposes. If you by chance have some sort of recording software running at the same time that you are attempting to run a show, the software could possibly be causing the microphone delay. Just a thought