Hrm, there goes the services theory. Though just to be clear, that first 94 was before you clicked on the .mp3, after a clean boot? That second arrow pointing at the first 94 makes it a little unclear.

I looked on my Windows 7 VM, and found Windows Media Player was starting a service called "UPnP Device Host". Can you check your services control panel to see if that service is set to manual, automatic or disabled?

Also, lets give Tony's theory a test (especially since I'm seeing a network related service startup here). Ready for some more DOS-fu?

This time, lets watch the network connections your computer is trying to make during this time. If we can find some stray communication to somewhere, blocking it locally may result in reducing or eliminating the delay.

You will want to run this before you open Media Player the first time, and preferably with all other network related programs on the computer closed including file explorer windows:

Then open a MP3, wait till after Media Player has finally started, then in the DOS window hit Ctrl-C to stop the netstat command. You will have a net.txt file in the directory you ran the command from. Take a quick look before you post it here, to see if there is any info it reveals that you don't want available to everyone. My plan is to look through it and see if I can identify a new connection related to Media Player.

What the command above does:
netstat - program to show various stats about what connections your computer is making to other computers over the network.
-a tells netstat to show all network connections, including ones in a wait state.
-b is a flag to show the EXE name that started the network call. Many will show as svchost, meaning it's a service generating the call.
-o also shows the PID of the process making the call, allowing some separation between all the svchost processes.
1 - Tells netstat to loop every second and make a new report. This is why Ctrl-C is needed this time, to exit the loop.
> net.txt is redirecting the output of netstat to net.txt, to make it easier to share instead of trying to copy and paste out of a fast scrolling DOS window.

My hope is that with this, we can see any network calls Media Player might be doing the first time to see if it is a timeout issue.