My laptop's local area connection (ethernet) keeps disabling itself. O_o

Sorry if this is in the wrong section, I'm not that tech savvy.

2 days ago I started having this problem. If I leave my laptop turned on overnight (it goes into sleep mode) ...the next day the local area connection has been disabled. I'm not sure what is causing it. I usually go to sleep around 4-5 AM and get back on the computer around 11 AM.

I can fix it easily by restarting the computer and re-enabling the connection, but it's annoying and shouldn't be happening. The restart is mandatory because the computer doesn't register the connection as being disabled (and thus possible to enable) until I do so.

I haven't installed, downloaded programs or changed anything on my laptop recently.

The only two potential culprits I can think of are my antivirus (Vipre) and TuneUp Utilities (came free with Vipre as part of a sales promotion.) I have had both programs on this laptop for about a month now. The reason I suspect Vipre is because I have my scans scheduled at 6 AM, which is within the time window that I'm asleep. TuneUp is supposed to optimize your PC and disables unneeded startup programs, but a google search has turned up nothing about it disabling ethernet. And why would it suddenly start doing this just 2 days ago?

I highly doubt the problem is a virus as AV scans comes clean and I consider myself pretty careful when browsing the web. I run script blockers and haven't downloaded anything except pictures recently.

A NIC not "waking up" from sleep or hibernation mode is a common problem on some desktop and laptop computers. Usually updating or reinstalling the NIC driver may correct the problem. But the easiest/quickest fix is to simply disable power manage on the NIC itself. A Google search will provide you with details/instructions and troubleshooting power manage on a NIC.

You have not provided details on the NIC's status in Device Manager (nor what OS you are using) when this problem happens. Check Device Manager to see if the NIC is actually disable and if so enable it. And if the NIC does shows up, try disabling it then re-enabling it.

If the laptop is configured to use hibernation then try disabling that option (thus leaving only standby).

Check the laptop Manufacturer's website and online forums to see if this is a known issue with your laptop and to see if there is a possible BIOS upgrade/driver fix or workaround for the issue.

Possible quick and dirty fix is to use Windows System Restore to restore the laptop to a state before this problem happen.

Disable sleep mode when running on AC power.

Since you say it does it every time, why not just shut the laptop down before you go to bed, and turn it back on when you get up? I find that it's always a good idea to reboot a Windows computer occasionally anyway, to keep things behaving.

Also, have you tried right-clicking on the network icon in the systray and selecting "Repair" or "Diagnose" (whichever is there.)?