Recently, I've been trying to play Fallout to no avail due to the constant CTD's that happen randomly after a few minutes.

The source of this crash is due to a file named l3codecx.ax. I've tried re-installing, updating, and replacing said file from a copy from my Windows XP CD. No dice.

Verifying the integrity of the game cache does no good, because every time I do so regardless of whether or not I play, it keeps saying one file failed to validate and will download a small file afterwards every time.

The first crash after this is caused by the New Vegas executable itself before the unannounced CTD's begin with the l3codecx.ax file causing the issues.

These are the partial crash reports.

Faulting application falloutnv.exe, version 1.4.0.525, faulting module falloutnv.exe, version 1.4.0.525, fault address 0x00661a74.

Faulting application falloutnv.exe, version 1.4.0.525, faulting module l3codecx.ax, version 1.6.0.52, fault address 0x000017de.