The Computer won't get to the Desktop Screen. It stops the process of logging in at a screen that shows a loading bar that keeps repeating.

I get this too. (Love using the solid blue background)

1. Check if there are any other users logged in on the Mac.
2. Log off all the users including yourself
3. Log in only on your user account and change the background

If that doesn't work, restart first and repeat.

If even that doesn't work, change to another solid background first and then change it back to the picture.

You will need to reset the machine to factory settings by holding in the "Reset" button with the power on. Then just wait until it reboots. If this doesn't work you may need to get the Operating System re-installed.

overheating?
did you do any hardware upgrade befor this problem?

hmm ok try this

restart computer with F8 pressed down and see if it goes to SAFE mode

if it does report back

Here are a few things you can do or try

Restart the computer. If you are already in Windows, you can do this from the Windows Start menu, go to Turn off computer and click Restart. As the computer restarts, watch for a progress bar at the bottom of the screen. press F8 about once every second. Immediately press F8 before the progress bar reaches the right side of the screen. From the Windows Start-up menu, highlight Safe Mode and press Enter. Wait for your desktop to appear, and then make the necessary repairs (for example, uninstall programs or devices). When the repairs are done, restart the computer, and allow it to boot normally.

Alternate:

From the Windows Start menu, click Run. In the Open field, type MSCONFIG and click Ok. On the BOOT.INI tab, check /SAFEBOOT.

Click Restart when prompted.

Turn Off the computer, now as soon as you hit the power button, keep on holding "Alt" key & keep on tapping "F10 key,ie: Alt+F10, it will open the recovery console ,select full factory restore and follow on screen instruction. (Note:this will erase all datas on the computer)

or

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

click start all programs accessories scroll to system tools from there you should see a system restore click next a sytem date should open up select the date you want to restore your computer to or if you want a full factory restore or

Turn Off the computer, now as soon as you hit the power button, keep on holding "Alt" key & keep on tapping "F10 key,ie: Alt+F10, it will open the recovery console ,select full factory restore and follow on screen instruction. (Note:this will erase all datas on the computer) or

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

Hope this helps don't forget to vote

load dell diagnostics and check your hard drive, one of the options when the dell logo is on the screen.

does this happen right after you power up your computer? or after the windows loading screen? if after the windows loading screen, what you can do is to restart your computer. while booting up, press f8 repeatedly and select safe mode.

If you successfully logged in to safemode, you can lower down the resolution.
you can do that by Right cliking on the desktop, click on properties, then change the screen resolution to a lower one.

Hope that works.

Seems to be your video driver (maybe). restart the computer when you see Dell logo start tapping on F8 key it will take you to advanced windows options. Select Safemode and press enter. login like you normally would . once you are on your desktop go to Start>all programs> accessories>system tools > system restore. Select the lastes bolded date and contunie to follow the prompts and your system should restart. You system will restart and it will state the system restore has completed. If not repeat the process by going into safemode with networking. once the desktop is up click on internet explorer and go to support.dell.com click on Drivers and downloads and search by service tag. down load the video driver in the video category.
hope that helps

See if you can boot in safe mode. Turn on computer and repeatedly press F5, select the safe mode option if you can get in then the problem might be you have too many start up programs trying to load when windows start. Find out which ones you do not need and prevent them from starting up when you log on.

before you get to the xp loading bar hit F8 a few times, youll get a menu up. boot in safe mode and try a system restore, make sure you pick a date to restore before the problem started. to find the option go to your start menu/programs/accessories/system tool/system restore

let me know how you get on