Ok, so an update.
When I made my earlier post, I had only encountered the "black screen on loading" bug for the first time and had only messed with it for a bit. I thought because the game played OK afterwards, that it was a one-time thing to start the game. Once I had an actual game started, I'd be good.
The black screen problem occurs any time the game loads. Loading between levels, loading a save game, etc. So the black screen was unacceptable for playing--I couldn't wait 5-10 minutes for each load.
I did some search and found this is a common problem. The Steam Forums in particular have a lot of posts about this bug. The takeaways were: the cause of this problem varies from system to system, and the only possible common factor may be some software interacting with the graphics card in some way.
I tried some of the common suggestons: closing my browsers, closing Steam, shutting off antivirus, running the EXEs associated with this program with different compatibility modes and with the "disable visual themes" and "disable desktop composition" options, getting rid of the Aero interface and going with Classic etc. My laptop does use Realtek audio, but I do not have an external sound device I can swap to (and IW wil not run if you disable your sound card).
After nothing was working, I got frustrated, opened up Task Manager, chose to display processes from others and started mass "end task"ing all non-MS processes that I could (I'd already shut down everything, and figured worst case I'd reboot my laptop).
Somewhere in the list was whatever was locking it. I've been able to load just fine now. I don't know what it was because I wasn't going to take the time to write down every process and test them. There was one for THXAudio that is associated with Realtek, but also some camera ones, a quickbar and some other stuff.
Anyway--the black screen problem differs for everyone, but it is potentially fixable for many.
/edit: Oops, forgot to add that I've even gone back in and turned some stuff on: reenabled Aero, opened Steam, opened a browser, now turned on my keyboard backlight and so far IW keeps working. I've not rebooted and reenabled all processes again--I am sure IW would break until I ended the magic process or processes again.
Post edited February 07, 2013 by notepad