My OS (Windows 7 Home Premium 64-bit) is fine now, but here's the situation:
I left my computer on last night and when I woke up, it was turned off. I originally thought someone turned it off, but when I tried to turn it on; the tower didn't even turn on. A few tries, and it turned on and I got a BOD message. After that, Windows started up fine. The only new change I've had is a new internet connection and the administrative events in the event viewer shows a bunch of connection related errors, mostly DNS client events, but it also had two service control managers, one dhcp-client, and one kernel-power as the source of events in the list.
The dump from the event log:
System
- Provider
[ Name] EventLog
- EventID 6008
[ Qualifiers] 32768
Level 2
Task 0
Keywords 0x80000000000000
- TimeCreated
[ SystemTime] 2012-06-15T15:19:30.000000000Z
EventRecordID 193133
Channel System
Computer MainAccountPC
Security
- EventData
5:03:16 AM
?6/?15/?2012
9705
DC07060005000F000500030010003400DC07060005000F000C00030010003400600900003C000000010000006009000000000000B00400000100000006010000
--------------------------------------------------------------------------------
Binary data:
In Words
0000: 000607DC 000F0005 00030005 00340010
0008: 000607DC 000F0005 0003000C 00340010
0010: 00000960 0000003C 00000001 00000960
0018: 00000000 000004B0 00000001 00000106
In Bytes
0000: DC 07 06 00 05 00 0F 00 ?.......
0008: 05 00 03 00 10 00 34 00 ......4.
0010: DC 07 06 00 05 00 0F 00 ?.......
0018: 0C 00 03 00 10 00 34 00 ......4.
0020: 60 09 00 00 3C 00 00 00 `...<...
0028: 01 00 00 00 60 09 00 00 ....`...
0030: 00 00 00 00 B0 04 00 00 ....?...
0038: 01 00 00 00 06 01 00 00 ........
Edit: Did some research and discovered the cause was probably an overheat.