I have a windows Xp operation system but whenever i boot it,it ask me options for booting like,safe mode,last known best configurations,safe mode with cvommand prompt,start windows normally.

But whatever option i choose,it shows the first windows screen and then automtically reboots and the cycle goes on and on.

Please can u suggest me what can be the problem.

The first thing I would look at is:
did you install any new hardware or software prior to this happening?

The next thing would be a hardware problem...and particularly the memory.
Download memtest and run it over night on your system. If it shows any errors at all...replace the ram stick that is failing!

Memtest86 - Download Page

The other issues is to open the computer and systematically remove and reinstall every connection, plug/socket, card that you have in the computer in hopes of it being caused by a bad connection! In doing this you should remove the add-on cards seperately and try to boot the computer....if it is a bad driver file then this will allow the system to not load the corrupted driver if the cards(hardware) is not installed.

Another issue would be to remove the drive and slave it to another computer and navigate to the windows properties and deselect the auto reboot tick so that you can reinstall the drive and have it boot to show the error code to give a clue as to why it is happening!

The last choice would be to just do a system repair using the second repair option on the XP installation disc to restore the operating sytem

i believe lurkswithin has said exactly wat i wld say too tell us if it workd after doing those tins

thanks for your suggestions,but how do i perform these tests when the windows is not even loading in atleast safe mode also,i tried your other solutions like removing the connectors and connecting again,but it did not work,the memory stick is fine,i have tried on the other computer and its working ,i feel its a windows problem and it may have to be reloaded again after formatting.

if you have any other solution pls let me know,anyhow thanks a lot for replying me

memtest is self booting. Switching the ram to another computer is not a correct way to check it. Use the program memtest as suggested.

to slave a drive to another computer is to remove it from the computer it is in and change the jumper on the back of the drive to "slave" and install it on the same cable as the other computers HDD in the middle connection plug. Depending on the setup of the other computer...you may have to switch the jumper settings to "master with slave" That is for a computer using a flat IEDE cable.

If the drives are SATA then just plug them in and it will automatically determine the slave drive.

Or you can use an usb external HDD enclosure. Install the drive in it (much easier)

Once installed and booted just navigate to the slave drive and system properties > advanced tab > system startup and recovery settings > uncheck the box to auto restart after failure. save and exit and shut down the computer. Remove the slave drive....reset the jumper...install it and start the computer. On boot when it finds a problem it will Blue screen and have an error code. copy the code EXACTLY as stated as it is what will tell us what the problem is that is causing the problem.

If that fails then you are left with only 2 possibilities....
Do a system repair using the SECOND repair option from a M$ xp installation disc.
Read the section Windows Installation CD - Repair Current Installation:
Accessing The Different Methods of Repair Available in Windows XP
for complete instructions .

The second possibility is to do a complete reformat and reinstallation of the operating system.

OH yes...one last possibility....send it to a shop