Resolved: What Is dxva_sig.txt And How To Get Rid Of It?

How can I get rid of dxva_sig.txt ?

This is like a toothache that is getting worse and worse. You had probably noticed it for some years now - each time putting it off with - "I'll do it after I watched this exciting movie" - if you know what I mean. ;)
Finally one day you can stand it no longer and so here you are ... and you have questions.
Q1: Every time I play certain .wmv and .avi video files, I noticed that a file called dxva_sig.txt is auto-generated in the same folder those movies were in. There is nothing but an "A" (or "B") inside the file. I can do nothing but manually delete it after it is generated. But then it gets regenerated when the file gets replayed. Is there a setting somewhere which I can change to prevent this file from being created?
Q2: Is this a virus infection of some kind? How do I get rid of it by preventing it from being auto generated and cluttering my computer?
A: Watch less prawn movies with .wmv extensions. And it'll be generated less. ;)
You can also try other remedies shared below.

What Is dxva_sig.txt ?
The "dxva" in dxva_sig.txt stands for "DirectX Video Acceleration", and it's some kind of debugging file that is auto generated when you play certain .wmv and windows media encoded .avi files; ...
Hell, I wish I knew the whole story. All I can say is WTF, let's cleanse our computers of them, and not let them ruin our movie viewing experience.

Create A Test File:
First, we need to be able to methodically duplicate the generation of dxva_sig.txt, so that later we can confirm whether we have rid of this menace for good or not. Don't stop now, this may look harder than it is supposed to be, but once you get past this section, it will be easy, I promise! ;)
1. Start by searching your computer for movies which has .wmv (NOT .avi, as it'll be harder) extensions, your hidden stash of prawn movies is a good place to start. -_- Go through one by one until you can find one that has a small size, and generates dxva_sig.txt as not all .wmv's or .avi's files create this file, only certain ones.
If you are not sure exactly where to begin, try using the Search function in Windows Explorer to find them.
That means, from the Start Menu, open up Windows Explorer (NOT Internet Explorer!), and find "dxva_sig.txt" using the Search button. Depending on your version of Windows, and whether you are using standard or classic Windows GUI, the steps are different - so I'll just let you figure out the steps above yourself.

2. When the searched results lists have built up substantially, click on some small sized .wmv file one by one, until you find one that generates dxva_sig.txt after a few secs of playing. Note the player that you use to play this. Normally the players known to create this file can be Media Player Classic (MPC), Media Player Classic - Home Cinema (MPC-HC), Zoom Player, or Windows Media Player 9 (WMP9) and below. Begin with one player, and continue to other players that you may have on your system. Note the culprits.

3. When you found one .wmv that generates the dxva_sig.txt file - let's suppose the .wmv file is: "prawn-sandwich.wmv" - rename it to "prawn-sandwich --generates dxva_sig.txt.wmv"
(This is so that later, for the purpose of this article, and much later, for your own purpose, you can always recheck whether this thing has come back to life after we killed it).

Which Media Players Don't Generate Them?
Use Windows Media WMP10 and above, or VLC. These 2 players shouldn't generate that pesky file.
As already mentioned above - MPC, MPC-HC, WMV9 (and below), as well as Zoom Player, will create the dxva_sig.txt file. There are so many other media players that may also generates this file - so please share with us - if you find one - in the comment section below.

How To Get Rid Of dxva_sig.txt?
If you have WMP9 or below, upgrade to version 10 and above.
If you need to use MPC, MPC-HC, or Zoom Player, you still need to try the steps below to prevent the annoying dxva_sig.txt file from being generated.

On systems with an ATI video card or integrated graphics:
You will need to disable Windows Media Video Acceleration:
1. Open up ATI's CCC or Catalyst Control Center.
2. From the menu, click on "View -> Advanced View".
3. Find the "Video -> All Settings" branch.
4. On the right pane, scroll down and uncheck "Windows Media Video Acceleration".
5. Click "Ok", and REBOOT your computer even though you are not prompted to.

For those with an older ATI driver which doesn't make use of the Catalyst Control Center:
The WMV acceleration setting is in the Windows Desktop properties:
1. Right-click on the desktop and click on "Properties".
2. Go to "Settings" > "Advanced".
3. Look for "WMV9 acceleration" or something similiar, and uncheck it.
4. Click "Ok", and REBOOT your computer even though you are not prompted to.

Note that this problem is also present on some Nvidia's cards, not just ATI's.

IF AFTER REBOOTING, and testing with the above mentioned test file, you still have this problem, try out these other solutions which were suggested in some forums elsewhere in the net.

-Start > Run > "dxdiag" > Display > AGP Texture Acceleration [Disable]
IF you unchecked the "Windows Media Video Acceleration" above, this is probably already not available.

-For Media Player Classic
MPC > Display > Options... > Output > WMP7 (without rendering)

Last Resort: If You Still Cannot Prevent It From Being Regenerated:
As a last resort, just set Windows to always open the .wmv and .avi extension with Windows Media Player 10 and above, or VLC, and not with whatever other movie player you may be using. You can still use your preferred movie player to open other extensions, no problem.

A Final Word
Btw, if you're still using codec packs, like K-lite pack (which includes MPC and/or MPC-HC, depending on which pack), you may like to try using MPC-HC (with its own decoders) alone to open your media files. That means be rid of codec packs. For the extensions that MPC-HC can't open, like Real Media (.rmvb, .rm, etc) files, use VLC to open them. This will save your computer from having a bunch of codecs generating lots of different errors. If you really need a certain codec - because you can't get VLC or MPC-HC to play them well enough - get it direct from their original developer's website. Not from third party codec packs.

Hope this helps.