Help installing from Disc

[HalbesPint26]

I can't find help anywhere else, so here goes.
I have a Call of Duty: Modern Warfare 2 disc I bought from eBay. I have tried to run the install disc, but when it runs, steam says:

"An error occurred while installing AppID 0: 'invalid backup path'"

I have tried to install it multiple times, looked to Activision forums, other steam discussions, Microsoft help, and none of them have any answer.

[true professional]

According to https://www.reddit.com/r/steamsupport/comments/157cdoy/comment/jvzcdt1/?utm_source=share&utm_medium=web2x&context=3 , you might've gotten ripped off.

[HalbesPint26]

I don't believe so. I entered the code first time I put the disc in and it said it worked. The issue is that it won't install. Thanks for answering though.

[tyl0413]

You don't own the game on this account, try redeeming the code but it's most likely used so you need to buy it off Steam.
Regarding physical install issues Steam recently changed the way they do their backup installers which also cause issues with official game discs, I haven't had much luck with them myself on the newer Steam Client versions. Disappointing they broke it.

[Stifler]

Selber schuld du geiziger ♥♥♥♥ wenn du mw2 als cd kaufst