Right Click on SC: Conviction in your Steam Library.
Click on Properties → Manage → Browse local files
Now open src and go to → system
Right Click on "conviction_game" and choose under "Compatibility" the Windows 7 option.

What the title says

ubisoftconnect.com

The biggest problem that other guides seem to miss (and even Thirteenag's patch doesn't seem to fix) is deleting systemdetection.dll.

If, like me, you downloaded the patch first and wondered why it didn't work later. It seems like the script from the patch is still looking for systemdetection.dll (which it tries to skip) even after deletion.

At the time of writing, the patch is 166 days old and cannot be used with the game without crashing.

If everything worked out the way it should, you should get this message on startup:


If you click OK or press ENTER, it either disappears the first time or it appears a few more times.
(This popup will appear every time you start the game, but it won't stop you from playing.)

It doesn't matter because now Ubisoft Connect will open and ask you if you want to redeem Splinter Cell Conviction on your Uplay account.

Of course we do and after redeeming the game we can either play SC from Steam or Uplay.

Now the game should be fully playable!

Go to C:\Program Files (x86)\Steam\steamapps\common\Tom Clancy's Splinter Cell Conviction/data\Videos

Look for the following files:
Logo_Clancy_01.bik
Logo_ESRB_01.bik
Logo_ESRB_02.bik
Logo_MiddleWare_01.bik
Logo_Ubisoft.bik

Rename these files to:
Logo_Clancy_01.bik.original
Logo_ESRB_01.bik.original
Logo_ESRB_02.bik.original
Logo_MiddleWare_01.bik.original
Logo_Ubisoft.bik.original