I have to restart to connect to internet

My PC motherboard recently failed (a Dell Studio XPS motherboard). I replaced it with an ASUS sabertooth motherboard. Ever since then when I turn my PC on it usually doesn't connect to the internet. I have to restart the PC to get it to connect sometimes I only have to restart once, other times I have had to restart up to 7 times before it connects with no consistent pattern.

I thought the onboard lan connection might be bad so I installed an intel network card, but the problem still persists.

My internet provider is time warner cable. The PC seems to be able to connect to the router since I can type in it's address to view the router configuration. The PC is connected by a cable to the router.

I have a Linksys WNR2000 router. My 2 other PC's are also connected by cables to the router and don't have this problem. I also have an Xbox, tablet and my phone that can connect wirelessly to the router and don't have the problem. I tried shutting off all the other devices so the PC was the only active device on the network and there was no difference.

I believe the problem is with the PC since the only thing that changed was the motherboard in the PC and this problem appeared right away.

I have tried enabling and disabling the lan card with no change. I have viewed the log on the router and it shows the pc trying to use 1 of 2 address (192.168.1.53, and 192.168.1.59), and when it does connect, it is on one of those address.

I am using Windows 7 Ultimate edition 64bit.

Any help is greatly appreciated!