Frequent Internet Disconnections PC related?

My internet is frequently disconnected. I discovered that after a disconnection if the PC is rebooted the internet connection is restored. This suggests that I have some problem with the PC. I have run sfc/scannow and chkdsk c:/f this has not helped.

I also see another problem In WindowsLivemail12 at times I get this message "A problem occurred while trying to open this message
A problem has occurred Please try again"

This also goes back after rebooting, sometimes once at other times twice.

My question is what can I do to correct or vindicate my PC