Well, I did see the total stoppage of just about everything in your trace all at the same time, and the odd thing is, a driver
loads just as everything is stopping - avast (aswsnx.sys). The fact that, right as everything is freezing, the avast driver loads.... frankly, that's very, very suspicious. What is happening is that once the system is up, it looks like explorer.exe is parsing your E: drive, specifically the Music folder - this consumes almost 100% of the disk's time, which is fine - CPU usage is normal, etc. However, *as soon as the avast driver loads*, the entire system comes to a halt, CPU time drops to 0% used, 99% idle, and the disks go virtually silent.
Honestly, if this were my machine, I'd be uninstalling Avast (and making sure the drivers
are actually gone after the reboot), and I'd try again to see if the problem continued. This could be a red herring, but it doesn't look like one. Here's the relevant data - the top portion of the graph shows disk activity, and the bottom shows driver load and delay - note that you can see ntfs and filter manager (ntfs.sys and fltmgr.sys, respectively) get called multiple times in sequence, which means a driver is loading (and the disk is being hit to load it) - what comes after is the avast driver, which is the *very* last activity in the trace you took. Again, it *could* be a red herring, but it's not likely.