Windows 7: Problem with local area connection and video card with more then 3gb

Upgraded to window 7 64 bit from vista 32 bit. Did the custom install like it said. With Vista I had 6GB of memory in computer and it showed all 6 in the system information and everything worked fine(yes I know it wasn't using all 6gb). After the windows 7 64 bit install if I put more then 3gb in my local area connection will not configure a valid IP address and windows turns off my video card(gts450) because it says there is a hardware problem(card is fine tested on another computer). If I just have 3gb installed the local area connection is fine and so is the video card. My system is 64 bit cpable and the motherboard supports up to 8gb. Max memory was unchecked but now I have to have it checked and maxed at 4096 to make my video card work and get the local area connection configure an IP. The ram sticks are fine, I have used all of them in diffrent configuraions for the 3gb(2-2gb 2-1gb). I have tried everything I can find on the web about anything remotely resembling this to no success. My BIOS does not have a memory remapping feature but again if 6gb was working fine on a vista 32bit OS why won't they work on a 7 64 bit? I even called microsoft tech support about the local area connection problem and they couldn't figure it out. Any ideas would be helpful.

More info please,

Motherboard model number, what memory you have and what timings they have,

If the timings are different then this could be the main cause, remember Vista didnt use all 6 gig so thus ignoring the ones that are faulty and using the ones that are ok too use.

The motherboard is a F690VGM(yeah I know not the greatest but has been doing it job). The 2gb sticks are DDR2 6400 and the 1gb sticks are DDR2 5300. I thought about the diffrent speeds but again with a 2gb 6400 and a 1gb 5300 in everything works. Should say when I check max memory and max it out at 4096 I can have 4gb installed and there are no problems but if I uncheck it then I lose my local area connection and video card with the same 4gb installed.

Not sure if it's your board or the install but something is up.
Have you tried a reinstall of 7?
Are you totally sure you are using the 64bit version of 7.

Before installing 7 did you move the memory around in the slots for any reason.

I think MRDEMON hit on a good point with Vista only using 4GB and not looking at the other 2GB. could be that is the ROOT of your problem, those 2 1GB sticks of RAM.

A good rule of the thumb. Don't miss match your memory. Your computer will works with miss matched memory but not correctly. Same brand, part number, speed ect. Now is the time to buy ram because the prices have went way down.

Good rule of thumb yes but not hard facts.

In my new desktop I have 8GBs of Kingston memory and 8GBs of crucial memory. The only thing they have in common is the voltage they work at, 1.65V. Speed and timings are different. The motherboard used the lower timings for both. The OS doesn't care as long as the memory isn't bad.

I suspect that the 2 1GB sticks the OP has are not very good and he used the 2 2GB sticks in the first 2 memory slot so Vista 32 didn't even go near the other 2 sticks. Now with 7 64bit it is looking at using all 4 sticks and can't because of poor memory.

Thanks for your reply Shootist. You are correct. My thoughts were not to get into timming/volts ect. for a nube. Thinking that just the proper matched ram would solve the OP problem.

Well I think it's not really the mismatched RAM as bad RAM.

The only way to tell is to run MemTest86+ for a long time. Like at least 10 hours.

Again the first thought I had was the memory. However I have used all 4 sticks of ram in diffrent configurations for the 3gb when the system works. Lets label the first 2gb stick as A the second 2gb as B one of the one gb as C and the other as D. Stick A and C only in computer everything works, stick B and D only in computer everything works, stick A and D only everything works, stick B and C only everything works(this is all with max memory unchecked) but if I put A,B,C or A,B,D or B,C,D or A,B,C,D in at the same time nothing works. Now the really weird thing is if I check max memory and set it to 4096 I can install A,B or A,C,D or B,C,D and everything works. Makes no sense since everything I have read says max memory should be unchecked. So there does not seem to be any way that it is the memory sticks.

Do you have a extra hard drive?
If you do pull out the one that is in there and install the other. Install ALL RAM sticks in whatever configuration you like.
Do a fresh install of Win 7. If you are using a upgrade disk you can follow the instructions in the tutorial to use the upgrade DVD to do a clean install Or you can do what I did which was to COPY the Windows folder from any other system/hard drive onto the hard drive you are installing Win 7 on with a upgrade DVD and the install routine will see that old Windows folder and allow the install to go forward. Delete all partitions, create a new partition or partitions and format it.

See if this new install sees and uses all the RAM and lets your NIC work with all the RAM installed.

That's about the only thing you can do at this point.