Dr. Niko,
Jon put it succinctly, but I will be more specific. (Actually, read my post above).
There are two places on WIN7 to make changes to power. One is on your NIC card. These generally have little effect on your networking. The other is under Power Options in Control Panel. As usual, Microsoft makes it more complicated than it needs to be with all these power plans, etc. as if you are going to change them constantly. But, you can change your settings in a number of ways. The simplest way is to go to the left side and change the settings of "Choose when to turn off the display," and "Change when the computer sleeps." Personally, I recommend changing both of these to never.
There is absolutely no reason to have your computer sleep. It is not going to save you much energy, and it is going to cause you these problems. If you only had one computer like you probably do at home, then sure, go ahead and sleep away. But, in a production environment where you are trying to network and use databases, the computers need to be on, awake and functional.
As far as the monitor, I would imagine I will get more of an argument. Again, personally, I hate having to move the mouse back and forth to get the monitor to come to life. I like to be able to walk around the office and see the screensaver and know everything is working. If you see a monitor that is not showing a screensaver, it may alert you that something is an issue.
One of the nice things of having a server and a domain is Group Policy. I can use group policy to insure that every computer on the domain cannot be changed to hibernate, sleep or have the monitor turned off.
Try this:
Set every computer to stay on all the time. They can log off or lock, but do not sleep, hibernate or even shut down (which wouldn't affect database connection but still).
After this, come in a few mornings, and if you have any issues with not being able to connect, let us know. It is always best to log off, but if the computer is only locked, then you know you will have a connection, because nothing is changing as far as that goes. The only downside to not logging off and just locking is, ironically, that very thing. That computer is possibly connected to the database, which can affect things like backups, but not always.
