For those having PC problems either getting started, crashing, or CD key errors ALSO Homestead bug

[naomha]

First and foremost. If your CD key is NOT working. Try updating Uplay with this link.
http://uplay.ubi.com/en-US/ then reboot and try again.
If you are getting the VC Redist error when trying to install AC3, please try these links for your appropriate system. Please note, x86 is for a 32bit system, x64 is for a 64 bit system
x86- http://www.microsoft.com/en-us/download/details.aspx?id=5555
x64- http://www.microsoft.com/en-us/download/details.aspx?id=14632
IF YOU ARE USING NVIDIA cards, it has been noted that rolling back to driver 301.42 and 306.23 have shown to increase perormance and problems associated with getting the game running properly, if at all
Please make sure you PC meets the specs. Laptops ARE NOT supported folks. If you get it to work, kudos. If not, again, it's not supported.
If you're getting wicked slowdown in open environments, turn of Vsync.
If you're getting wicked slowdown, turn off Physx
If you're stuck at the Homestead tutorial, reboot and try again. Also, make sure you are in the Homestead while this tutorial is active.
If you're having problems with a dlumd32.dll error. Try downloading this fix. http://www.displaylink.com/support/downloads.php
Make sure your Firewall isn't blocking AC3 access. Simply Alt-Tab out of the game and see if the Firewall window is open. If it is, allow AC3 access.
Make sure you antivirus is up to date, also your router's firmware
If you're getting a d3dx9_27.dll error, make sure DX is up to date here: http://www.microsoft.com/en-us/download/details.aspx?id=35
If you're getting freezes on an overclocked system, reset your graphics cards.
If you're getting CTDs or Black/White screen, try to run the game as administrator.
If you have NOT used your CD key, Steam will usually reimburst you for the game within the first 24 hours.
Above all else, please post specs and EXACT problems. It doesn't hurt to post a DXdg and to attach a screenshot of the problem if possible.
If an experienced or even novice user can not help or assist you on these forums, or you just can't get your game to work on your system, you can contact UBI support here: http://www.ubi.com/US/Support/Default.aspx
Good luck and happy gaming!
EDTI: You can also disable FXAA in the ini folder to increase fps when playing AC3. It is in there, Make sure you look for MULTISAMPLING. Set it to =0.
EDIT: Thanks to Nemesis for this find. Please check the link and do what it says exactly:
steam://openurl/http://forums.ubi.com/showthread.php/727611-AC3-Stuck-in-the-Introduction-to-stockpile-and-trade?p=8717862#post8717862
Also, if you are still experiencing wick slowdown, stutters. Please make sure you check your AA and make sure it is at normal or off. This should help a LOT!
If you are getting the "AC3SP.exe stopped working" error. Try to launch your executable from within the STEAM directory. NOT from your desktop or the Library folder. From inside the AC3 folder itself. That has been shown to help a lot of others as well.
IF you are having problems with an Nvidia 500 series card, try this fix here: http://forums.ubi.com/showthread.php/697120-Solution-for-GTX580-crash-display-driver-stoped-responding-but-has-recovered

[Freyar]

"Turn on PhysX"... are we basically forcing it through the NCP or what?

[naomha]

You want to turn off Physx if you're getting slowdowns in open environments. If you're in Nvidia control panel, choose "set physx configuration" on the left menu, disable it. Select "CPU" to do this. This may or may NOT work depending on your processor and graphics card. Sorry, I'm not an Nvidia user any longer, so I'm not up to snuff on Nvidia's CP any longer. I'll will still try to help where I can.

[BubbaBubbs]

naomha:

i really appreciate your effort trying to help myself and others.. just saying thanks..only thing i havent tried is the old driver roll backs...going to do that now and see what happens....

[naomha]

Best of luck. I've seen many posts stating that rolling back Nvidias drivers seem to be the problem. In fact, about every single machine having problems seems to be with an Nvidia card in it. Not all, just most

[BubbaBubbs]

thats actually kind of ironic since there were three 6 series nvidia cards that shipped with ac3 FREE lol. shows a SCARY qa problem over at ubisoft. if i had stock, scary enough for me to pull it over this...far cry was an AMAZING game, i wonder if there are any major different personell at ubisoft now (far cry was a WHILE ago)..stil trying to find the rolled back drivers

[Freyar]

I'm in the process of installing 306.23. I'll report if any changes are observed. I'll have it to a clean install.

[naomha]

Just look under older/legacy drivers under Nvidia's driver page

[Freyar]

306.23 had no changes. Attempting 301.42

[naomha]

301.42 seems to be the majority that most users have the most success with.

[Freyar]

301.42 gave an extra 4 FPS, a 16% increase, but at the cost of major conflicts with other games like Planetside 2.

Even then, 4 FPS isn't strong enough to really solve the problem.

[naomha]

Try stopping FXAA through the ini folder. That may raise your fps a lot higher as well. Sorry 301.42 didn't give you the boost you needed.

[Freyar]

I really hate that they try to force any form of AA. I typically don't want it, especially FXAA as it's just a blur filter. :P

[naomha]

Unfortunately, it's in almost every game nowadays. Try stopping that. That may give you a huge increase in performance

[Freyar]

At this stage, I think I'm going to be pushing a reformat as well.

[naomha]

I wouldn't go through all of that just now. Just try stopping the FXAA. You're trying to fix a small problem by hitting it with a jackhammer. That may be unneccessary.