Have you tried restarting your computer (NOT ACTUALLY JOKING). I had the same thing happen and restarting actually fixed it, but it would be fun to know what is actually causing the problem though.

Yes I did. I just did it another time to make sure. I'm currently installing windows 7 on my lappy and see if it works on that.

Alright it works on my lappy so the problem is local.

ipconfig -flushdns (in cmd)

And do you want a bit before starting Steam, or the moment your computer starts up, you click on Steam?

I also cant start steam, it shows the go offline or retry box, I know I have internet cuase Im in mumble and posting this, please help :)

can you see steam.exe in task manager after it crashes?

http://i.imgur.com/Z0IIYjv.png

I've never been able to not clear the DNS cache before. Something is wrong.

Nope.

I could be wrong, but when you reset your modem (hold the reset button down for xx seconds) doesn't that also flush your dns?

I'm pretty sure just restarting your computer flushes your DNS. I'm gonna try resetting my modem anyways.

I usually disable windows services that I don't use/need. I tried enabling all the default services and I'm starting to get this.

http://i.imgur.com/HRMVeIj.png

Fuck it, I'm reformatting.

I'm pretty sure I'm having this problem because I used ccleaner's registry cleaner. I knew you shouldn't do it because it doesn't actually fix anything but I did it anyways because why not. If you're reading this you should never use a registry cleaner. If something is wrong with your registry you fix it manually with instructions from google. Registry cleaners don't actually make your computer faster or anything.

I know you said you already tried restarting but I had that problem a few days ago. It was an issue with my network, not my computer itself. Just unplug your modem for a few minutes and restart your computer. Easier than reformatting if that's the case (unless you already started).

Close mumble relaunch Steam

I've already reformatted my computer and steam installed fine without needing to fiddle around with my modem. Prior restarting I unplugged my modem for about 10 seconds so I don't think that would've fixed it.

Interesting. I actually have mumble start on boot.

I have never seen DNS cache causing steam to crash. It was most likely mumble. Next time it happens kill mumble completely from task manager.

Had the same problem, i couldn't fix it so i reinstalled windows

It could be Mumble, that's why I was asking if you open Steam right away or do you do other things first.

ipconfig /flushdns works though.

kissme edited his post and now this post is useless.

:D The moment I hit 'post' I was like....wait..../ works too, I forgot lol

Edit: Incase it still isn't working for you, just for the hell of it, try starting your computer up in Safe Mode with Networking and see if it works. Sometimes SMN has problems with wireless, but it sounds like you're hard-lined, so you should be fine.

hey you should check out your video

http://www.youtube.com/watch?v=YwoM3WqGiwQ

I just replicated the problem. Both times I was messing around with my QoS settings for the steam ports. But the problem stuck even after I'd disable QoS. I fixed it by booting into safe mode with networking, launching steam, turning off safe mode and rebooting.

I know you've resolved your issues, but...

Restarting your computer does not flush DNS.

When you try to flush the DNS, Windows needs to use its DNS client service. If you have that disabled, you will get the "function failed during execution" error listed above. If you used a registry cleaner, you likely destroyed critical entries which caused the service to fail to operate even if it was started.

Unplugging your modem for 10 seconds will likely have no effect on anything--most cable providers have timeouts of 2-5 minutes, meaning you'd need to unplug your modem for that long in order to fully troubleshoot any issues or to pair your modem with a new MAC address (if you were trying to troubleshoot a router by plugging directly into the modem, etc).

And finally... Registry cleaners. Registry cleaners can definitely speed up a computer, but the speed difference is minimal on even somewhat-modern hardware. Registry cleaners are far more effective when used properly--to eliminate errors (typically from corrupted/poorly uninstalled software). If you do not have errors occurring, you should probably not touch a registry cleaner. Most registry cleaners offer some type of disclaimer because they are unintelligent pieces of software that look for empty keys and/or use other flags to determine what to delete. The problem with this is that there are many thousands of keys that are intended to be empty. There are some registry cleaners that intelligently ignore hazardous registry locations, but in general, they are more destructive than productive.

Okay I found the actual problem. I was using nvidia beta drivers. Went back to the stable release and everything is fine.