It Keeps restarting at the loading screens

Reset BIOS by removing coin battery.

It could be because your hard drive is failing.

Try booting from a bootable CD. if it gets past the dell splash screen it's got to be the hard drive.

Restart your computer
During the boot process you will see on the screen to press a certain key to enter setup usually the Delete or F2 key
this will vary depending on your computer and operating system

Press and hold that key during the boot up process to enter BIOS using the arrow keys load failsafe defaults or load optimized defaults press escape then press f10 to save to cmos to restart

hope this helps

If this is all you see when booting it can be may things. CPU,Motherboard, RAM issues. Are you hearing beeps? if so how many? This will usually tell you what the issue is.

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

Immediately after seeing the Dell logo, keep tapping the 'F8' key,
until you see a "menu" (white text over a black background)
giving "startup" options for Windows XP.

Select "Safe Mode" and see if you can start in that mode.
Then, use "System Restore" to go "back" in time, to the most-recent checkpoint (date/time) where your computer _DID_ work.

Restore to that point, and restart.

are you using windows? just reinstall your operating system, this may keep it back to normal

If the computer has been moved recently, I would chack the Video card in the mother board to make sure it is seated in the slot all the, Unless you have on board video.

Tap the F8 key when booting up. This brings you to a screen with different options. Choose Use last known good configuration. this should solve the problem. Your system is stuck in a loop.

Please don't forget to rate me.

Get the proper- FREE download from dell here: http://support.dell.com/support/downloads/download.aspx?c=us&l=en&s=gen&releaseid=R113575&SystemID=LAT_PNT_PM_D600&servicetag=&os=WW1&osl=en&deviceid=3083&devlib=0&typecnt=0&vercnt=7&catid=-1&impid=-1&formatcnt=1&libid=6&fileid=148994
load that and see if it works. If it does not there is something faulty with the video hardware. Make sure to remove all the other video drivers in there first. Hope that helps!