Windows 7 - No sound after RAM upgrade - Windows 7 64-Bit

My PC - as described by SiSoft Sandra 2010
Make - Packard Bell - Custom
Motherboard - Packard Bell PT890-8237A
CPU - Intel Core 2 Quad CPU Q6600 @ 2.40GHz
Memory - PNY 4GB DDR2
Graphics Card - NVIDIA GeForce 8500 GT - 512 MB
Total Storage - 620GB

Hey guys, please bare with me as i try to explain my problem, i have been using this PC now for 2 years with no problem but decided to start upgrading it starting with the RAM, It originally had 2GB RAM so i decided to upgrade to 4GB which i did yesterday, I turned My PC off then disconnected the PSU power cable, I then swapped the old RAM out for the new RAM, Reconnected the PSU power cable and booted PC up with no problems, I then went to start playing FIFA 12 and noticed i had no sound, I thought i might of had a connection problem with my Turtle Beach X41, So after checking all the wires i tried using Realtek audio manager to switch from stereo to digital output as my Turtle Beach uses an optical cable and sometimes i forget to switch it back from my stereo sound system, I then noticed that Realtek Audio Manager has disappeared completely from my PC and i cannot find anywhere to download it again, So after an exhausting 4 hours surfing the internet to try and fix my problem and trying several ways to get sound back with nothing working i hope that someone here can help.

Here are the things i've tried,

I tried removing and reinstalling the drivers for sound, by going through device manager where i found that i have nothing relating to sound, which was confusing.

I then tried downloading the sound drivers and installing them anyway, this didnt work.

I tried going through BIOS to see if anything had changed in there and to my eyes nothing had.

I also tried removing the AC'97 and HD AUDIO cables from my motherboard booting up, shutting down, plugging them back in and booting up again, a random idea i found on the net... this didnt work

My last resort is to do a full format of my 4 hard drives and reinstall Windows 7 hoping this will bring back sound however i dont want to try that if its not going to work.

At this Point i dont know how to provide screenshots but i hope i have explained enough for someone to help.

Sorry for the long post

hi there

check out this link Latest Realtek High Definition Audio Codecs >>> Latest Realtek HD Audio Driver Version - Windows 7 Forums and try updating the realtek manager during the installation process it will remove windows driver etc and re-install the drivers plus the latest realtek manager software DRIVER VERSION: R 2.67

hi i tried those drivers and they installed correctly but pc is still saying that i have no audio output installed, to clear up any confusion its using on-board sound not a stand alone sound card. i just performed a full flash and reinstall of Windows 7 to hopefully bring it back which unfortunately it didnt, so thats leading me to believe its a hardware problem, if anyone knows would a new sound card overide the onboard sound which isnt working? or do i have to replace motherboard? and could someone link me a good site for PC hardware, cheap would be nice