After reinstalling my 727-100 and adding Matt_Alt_Mods I get a bing bang from windows,I think? Like the error sound.

I c/p the Mscvr71.dll from a folder in a saved temp folder I have.
I just got a new used computer with windows pro. I checked jsut now:
c:\Windows\Sys\Windows32 For Msvcr71.dll and it isn't there.
I need advice with this? Do I copy the one I put into my main FSX folder or download a new one? And where to put it??
I just loaded from 727 flights( KSEA) and had to reload the plane by Crtl+Shift+R to get the sounds; Is this right? When it loaded it was cold and dark, I started engines,but no cockpit sounds??? Then I realized I didn't have battery power on on the FO panel, after I switched that on and everything lit up I got the sounds.
I did add the line:

[electrical]
electric_always_available=1


berlopez :D