I tried to replace the wallpaper and I lost the wallpaper and the screen started shuting of after I stoped typing

To change the wallpaper on your Android phone, follow the steps below:
1.Tap and hold on the "Home screen" to open the "Add to Home" menu.
2.Select "Wallpapers" and choose the type of wallpaper you want to implement. Three options may be available: Gallery, Live wallpapers, and Wallpapers.
Note: Live Wallpaper may not be an option on some phones. This is due to the limitations of the hardware of the smart phone itself.

Gallery allows you to set one of your own pictures as wallpaper. Tap "Gallery" and select your preferred picture. You can crop the part of the picture you want to use as wallpaper. Then, tap "Save" to set the picture as your background.

Live Wallpapers provides you with a set of animated backgrounds. Tap "Live Wallpapers" and select the live wallpaper you wish to use. Next, tap "Set wallpaper" to set the live wallpaper as your background.

Wallpapers are a collection of pre-installed wallpapers. Tap "Wallpapers" and select the one you prefer. Next, tap "Set wallpaper" to set the picture as your background.

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if its got a touch screen sounds like climate control module failure had this before try a battery reset

Click to view downloads available (Samsung)
:
Download Artistic Wallpaper Collection for Samsung Phones (50 wallpapers - ZIP format)

Download Abstract Wallpaper Collection for Samsung Phones (16 Wallpapers - RAR format)

Download Movie Collection Wallpaper for Samsung (13 Wallpapers - RAR format)

Download DX Theme for Samsung

Download Woman Wallpaper Collection for Samsung (19 Wallpapers - RAR format)

Download Cars Wallpaper Collection for Samsung (18 Wallpapers - RAR format)

Download Windows 7 Wallpaper Collection for Samsung Phones (12 wallpapers - RAR format)

During the boot process you will see on the screen to press a certain key to enter setup
Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart
or you might try
During the boot process tap the f8 button three times this will boot into safe mode where the only things
working will be your mouse and keyboard enabling you to attempt to repair your computer

once you have your computer running
try uninstalling a few unnecessary programs then click start run type cmd then type chkdsk/r/f which will scan for and attempt to recover bad sectors and automatically fix any corrupt files on your hard drive then defragment your hard drive

hope this helps good luck

Have you tried looking at the Device Manager and the Disk Management console (assuming it is Windows)?
This article about troubleshooting external hard disks might be of help: http://www.devicedriverfinder.com/blog/device-errors/external-hard-drive-troubleshooting

Reinstall again your Automatic Wallpaper change. This might be the problem is your wallpaper changer, check the setting if it is TILE, CENTER or STRETCH, only this 3 options are available on wallpaper, aside from resolution if only for viewing purposes.

1. change your theme to windows classic and then setup your favorite wallpaper.
2. if this fails create a new user account and see if you have the same problem in it too. If no, you can use the new user account and delete the one which you are using currently.

try to reset the phone

type *2767*3855#

Try go to safe mode. press f5 during boot (for xp) and f8 for vista.