I've got a HP w1907v monitor and latly it has been going into sleep mode without warning while i'm using it. All my power saver settings are set to off.

SEEMS TO ME (BLIND) THE Pc is going to sleep mode.
and that is slow. coming out it is.
there is no need for screen saver (no PC TOLD) but screen saver is for destops using pre-2001 CRT cathode Ray Tube monitors
so don's screen saver.
or in control panel , power settings turn off sleep
all that is totally under your control unless you have bad drivers
seen in DEVICE manager

Control panel Power options adjust time for monitor time to sleep you can adjust 5 minutes to never the option available same can be done for hard disk. This is necessary as even monitor is active and when hard disk goes to sleep you may end up in same situation
Alternatively you can activate screen saver by
right click on desktop, settings screen saver choose screen saver set time to activate screen saver.

This may be something that Windows (or the computer is telling Windows) to do. Everyone wants to reduce the power consumption in the computer, so be default your monitor may be going into 'sleep' mode and turning off.
1) To change this, RIGHT click on the Windows desktop. 2) When the menu appears, select PROPERTIES, then select the SCREEN SAVER tab. 3) There are 2 things to check here. First at the top, make sure that your screen saver is selecting something beside BLANK. This will cause the monitor to blank out and appear to have turned off. 4) The second thing to check is the POWER settings. Click the POWER button at the bottom on the screen. 5) Now, you will see 2 rows of power options, one for when the computer is plugged in (which is all the time with your desktop) and the other is when on batteries. We're concerned with the PLUGGED IN settings. 6) Make sure the TURN OFF MONITOR setting is set for NEVER. This will ensure that your monitor never turns off on you. 7) Now click OK and OK and now your monitor shouldn't turn off on you.
Hope this response helps you out.
Best of luck!
I strive for '4 Thumbs Up'! If I've assisted you, I'd greatly appreciate you taking the time to provide me with a favorable rating. Thanks so much!

Follow this instructions to disable sleep mode
In windows XP
1)Right-click the desktop, and select "Properties."
2)Click the "Screen Saver" tab, and click the "Power"

button at the bottom.
3)Change the option next to "System Standby" to

"Never" for either "Plugged in" or "Running on

batteries" or both if that is what you want. Click

"Apply," "Okay" and "Okay" once again to close the Display Properties dialog.
In windows vista

1)Click the "Start" menu, and then click the Control Panel.

2)Click "System and Maintenance," and then select "Power Options."

3)Select "High Performance" to disable the overall sleep mode. The monitor will still go into sleep mode unless you click "Change Plan Settings" and disable all sleep options.
In windows 7

1)Click "Start," and then select "Control Panel."
2)Double-click "Power Options."
3)Select "High Performance" under "Additional Plans," and then click "Change Plan Settings." Change all of the options to say "Never."

I've seen on a few Windows 7 machines has been the display turning off after only 15 minutes, even though I set the Turn off the Display option to Never. Weird!
You're probably reading this because you've tried changing the power plan settings to Never for everything and your monitor still turns off! This can be very frustrating and usually occurs with new installs of Windows 7, though I've seen it happen on older installs too.
In this article, I'll go through the different ways you can fix this problem. Note that if your computer is on, but the screen is showing No Signal or No Input, you should read my post on fixing blank or black screens. Now let's go through the possible solutions.
Power Options - Control Panel First, we need to make sure everything is set correctly in Power Options. Click on Start and type in power options or go to Control Panel (icon view) and then open Power Options from there.
Click on Start, then Control Panel and then Hardware and Sound, and then click on Power Options.

Click on the Change plan settings link that is next to the plan that is currently selected. In my case, the High Performance plan is selected, so I'll click on the link next to it.

First, make sure that Put the computer to sleep is set to Never. Next, change the Turn off the display setting to whatever value you want it 10,15 min etc.. You don't have to set it to Never if you don't want to. After this, click on the Change advanced power settings link.

Expand Hard disk and then expand Turn off hard disk after. Reduce the value till it gets to Never. Click OK and then click Save Changes on the Edit Plan Settings page.
Screen Saver - Control Panel The second setting you want to check is the screen saver. Go to Control Panel, click on Personalization, and then click on Screen Saver at the bottom right.

Make sure the setting is set to None. Sometimes if the screen saver is set to Blank and the wait time is 15 minutes, it'll look like your screen has turned off.

BIOS, Graphics Card, Monitor The two methods above are the most common reason why your display will turn off after a set amount of time, however, there can be other possible causes.
BIOS - On some computers, the BIOS can have power saving settings that determine how the computer sleeps. These are called sleep modes (S1, S2, S3, S4, and S5). On some computers, you'll see an option called Deep Sleep Control. You may need to disable this in order for the computer to wake up faster.
Graphics Card - If you have a high-end graphics card installed, make sure you have the latest driver and management software installed. If you go through the settings, you may find an option that puts your graphics card into lower power mode or something similar.

Monitor - Lastly, some monitors have power saving features themselves. Usually, the monitor is supposed to go into power saving mode if it doesn't detect any input (HDMI, VGA, DVI, etc), but sometimes it happens unexpectedly.

You'll have to press the buttons on the monitor to get access to the monitor settings. Those are about all the reasons I could think of for your display turning off when it shouldn't. If you have any other questions please post them here ,Best
We Are Here To Help !!

install the driver for that monitor on the laptop

In windows click start, control panel, power options. On the first page"when the computer is plugged in" turn monitor off NEVER on the hibernate tab uncheck enable hibernation if checked, also disable sleep mode

right click on desktop - click properties - click screensaver tab, and dropdown menu to none. this turns off screen saver. For power/hybernate....
start - control panel - power options. Change all pull down menus to "never"

Problem solved.

Hi, Azrul here, from Malaysia. You can disable the sleep function for your HP Media Center m7250n before connecting to tv.

Go to control panel
then go to display
then go to power under the screen saver's tab
then set your power options to never go to sleep at any settings.

Hit the keyboard keys. It is better to just turn sleep and hibernate off and just use a screen saver or tun it off.