Random crashes after updating Windows 8.1

[Yozzer]

There is a pretty big update for Windows 8.1 out last week, introducing a lot of changes, (about 780mb), plus some fixes that came just before it. After the update, which required a fair bit of time when closing windows, and then a long pause whilst it counted up the percentage of progress before entering the windows itself again, after which I had some instabilities.
Within 20 minutes I had a crash to desktop when sorting some pictures, then again after a reboot to make sure the "fixes" were all in place OK. During the course of the next few hours I had 4 crashes to desktop, 2 when manipulating pictures, and 2 more when browsing, plus a few long pauses when looking at drives etc.
I wondered if the problem was being caused by the L2 cache no longer being in synch due to the massive update, so I disabled the cache I had been running with for some time.
L1 4gb, L2 8gb, no deferred write, on both my system drive and my data drive.
I de installed the updates, and tested the PC for a couple of days all OK. I then re installed the updates, and after making sure all was stable again, I created a new cache as before on both drives, and it has been running fine since.
It may of course have just been that one of the updates did not go in properly, but I thought I should report it in case somebody else has a similar problem with the 8.1 update.

[Support]

How does L2 Storage connect to the computer? by SATA or by USB? Thanks!

[Yozzer]

Sata, I have a dual boot system, (not used the old Win 7 system for some time now), so I created a 16gb partition on the SSD, (Samsung 256gb 840 Pro), and use that on my main Windows 8.1 for the two cache I have set up.
Eventually, once Windows 8 is fully evolved, I planned to use the SSD for my main drive, but to be honest, the system is so fast using the 840 pro for the cache, it is hardly worth going back, I might as well just use more of the SSD for cache and keep windows 7 as a backup.