Verified answer

System information is always helpful in trouble shooting problems.

As well as if your copy of ME2 is Retail, Steam, or Pirated.

From what you gave it sounds like your ME2 is out of date that when you installed ME3 it installed the latest PhysX drive which your ME2 is incapable of running. In short you need to update your ME2 to the latest version (v1.02 I believe). This will update your ME2 files to capable of using the latest version of PhysX.

How to do so:

Pirated - there's is nothing anyone can do, and nothing anyone should do to help you.

Steam version - Steam should, by default, automatically update all program files for you. However, this feature can be turned off, and corrupted data is not automatically fixed.

In the Game Library select the game's properties option (Right click the game and select properties) Under the Updates tab in the window that pop up you can check for updates, or verify game integrity which will correct any faulty files.

Retail version - First check for patch updates by visiting social.bioware.com and login to your BioWare/EA/Origin account. Under the "Games" drop down you can search for patch updates for your game.

If this fails, just uninstall ME2, and reinstall with the patches.

Mass Effect 2 Texmod

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RE:

Mass Effect 2 won't run- "failed physics system"?

It was running fine earlier today, but now it says "Failed to initialize the physics system. Please ensure you have an updated version of the Physx System Software installed." It started after I installed Mass Effect 3, so I dunno if that had anything to do with it or not.

I went to...