Since I installed pets I've been having some nasty crashes. Lately they are becoming more frequent and unpredictable. I'm using a laptop.

I downloaded the crash log analyzer and I had several possible causes. First was the DEP. I changed my settings as instructed though since then I did get a <unknown module> though. Haven't tested much after that.

Then I got as likely cause that my graphics card is the culprit. This struck me as odd since everything was working just fine before Pets. I updated my drivers but the game still crashes. (I'll elaborate more below)

I also got an "unknown".

What happens?
My game would freeze and I need ctrl + alt + delete my way out. Sometimes I get a message that program isn't "reacting" anymore and will be shut down.

Sometimes the game will "lag" all of a sudden and usually it would crash after. Usually it just freezes and crashes without warning though. The game runs smoothly until that point though even with all the settings set to high.

The last few tests I did was with a fresh installed game patched up to 1.31 without any mods or cc. I tried with settings set to high, medium and low. I've played while logged in and offline with the same results. The game would crash at random.

I never, ever get an error message though.

More complication
To make matters worse the dxdiag is inconsistent with what my system specs should be.
System Specs:
OS: Windows 7 Home Premium 64 bits
Processor: Intel Core i7 2G up to 2.9G with Turbo Boost
RAM: 8192 MB
Graphics card: NVIDIA Geforce GT 540M 2G
dxdiag:
OS: Windows 7 Home Premium 64 bits
Processor: Intel Core i7 2G up to 2.9G with Turbo Boost
RAM: 8192 MB
Graphics card: Intel HD Graphics Family 1760 MB

Apparently it's normal for it to list the "wrong" card since the nvidia one is supposed to kick in when needed. I'm not at all reassured by all of this though. Is there anything I can do about the crashes?

Because the 540M is not supported for Pets? You do know it has a yellow "Maybe"?

Have you reboot the system when you did DEP? And redo DEP after patching or confirm the setting is still applicable? As the process of modifying files (in Program Files) would sometimes reset Windows settings. The reboot is stated in the DEP FAQ.

I don't rely on CLA, as I prefer to do things manually. So, if you need help to interpret your CLA reports, you need to post in that thread; if you need my help in dealing with crashes, I need ALL the information asked for in this FAQ - Game_Help:Sims 3 Crashing Checklist^wiki. I'm going to edit this FAQ to include some more info, so you might want to back on it after a few hours...

Also, is the issue with just Sims 3 crashing? Then you need to post in Sims 3 Help!
Or does the computer crash or freeze even when you're not playing Sims 3? If so, then I apologize and please PM me so we can reopen this thread to deal with the whole system, not just Sims 3 issues.

*off to go be redundant and repeat myself obnoxiously on wiki*