Windows – computer wakes up without any reason

I've struggled with this problem before, and have only been able to do it on one of my PCs.

Some things to try:

• Does your PC have a wake timer feature in the BIOS? If not, it may not be capable of waking up to a schedule.
• Try changing the Bios sleep modes, i.e. S1, S2 etc.
• Also, the one PC I can wake up to a schedule has ACPI 2.0 enabled in the BIOS. (Not sure if that is relevant or not.)

Sorry I can't give you a definitive solution.

Unsure what your exact version of Windows is, but this site seems to indicate a similar issue is connected to “Wake on pattern match” issues in Windows 7. And the solution appears to be to disable “Wake on pattern match” under the advanced properties tab for that network adapter as shown below:

The Intel adapter panel has the “Wake on Pattern Match” option in the power management tab:

As for what “Wake on pattern match” actually is, this answer covers it nicely; it’s basically a lot of basic network activity:

The “Wake on pattern match” option instead checks for packets that matches the operating-system-specified patterns; for example, an ARP request for the computer’s address, or a TCP connection attempt.

In contrast, a “magic packet” is a unique an—as implied—magical/non-standard bit of network communication designed specifically for unique needs of wake on LAN setups:

The magic packet is a broadcast frame containing anywhere within its payload 6 bytes of all 255 (FF FF FF FF FF FF in hexadecimal), followed by sixteen repetitions of the target computer's 48-bit MAC address, for a total of 102 bytes.