I am running Windows Xp with SP2. Suddenly, system hangs when booting. It also hangs when running last known good configuration. In safe mode, booting stops on jgogo.sys, with message “Press Esc to cancel loading sptd.sys”.

First take your Windows installation CD and insert it in CD/DVD drive. You might need to change BIOS settings to make system boot from CD as first device. Boot system from CD (you will need to press any key when system asks you if you want to boot from CD). After few minutes, you will have a choice to install Windows or to Repair. Press R to start Recovery Console.

You will be asked which version of windows you want to boot. Usually you will have only one choice. Enter number next to windows version you want, usually 1 and press enter. Now enter your password and press enter

Lets assume that your boot disk is C:

On command prompt write:

chkdsk /p /r c:

Chkdsk command checks the specified drive and repairs or recovers the drive if
the drive requires it. The command also marks any bad sectors and it
recovers readable information.

When chkdsk is finished, type exit and press enter to reboot your system. Take out Windows installation CD, and let system boot normally.
If system still hangs, repeat previous steps to get to Recovery Console.

On command prompt write:

fixboot c:

The fixboot command is a Recovery Console command that writes a new partition boot sector to the system partition that you specify.

Type exit and press enter to reboot your system. Take out Windows installation CD, and let system boot normally.
If system still hangs, repeat previous steps to get to Recovery Console.

On command prompt write:

fixmbr

This command repairs the MBR of the boot partition.
Type exit and press enter to reboot your system. Take out Windows installation CD, and let system boot normally. Your system should boot normally