Need Some Help

Hi all im new here, just registered i was told i might probably get help for my problem here.

So i just installed 3 latest updates for xp and restarted, went to the bathroom while restarting and such when i get back there is a warning message "NTLDR is missing" CTRL ALT DEL to restart i do that and it happens again but now a message saying "Error Loading operating system" and just a blank screen so i start checking the boot seq and everything but i cant find anything wrong. So i put my xp disk in to try to boot from it and repair , nothing happens just the blank screen saying "Error loading operating system" but i can hear like its booting up it happens when i install a game and such but i get stuck with that screen. I cant even format.

So can anybody help me?

ok ill try that but the thing is its set to boot from cd first but i think i should just put it into my external hdd's box usb connected and format there.

bad harddrive, virus, did the updates come from windows update or what.

Ok i but it into my external HDD box formated it and plugged it back in and it still says "error loading operating system" so i did some **** in the bios and now it cant find any of the HDD's.

Thats the thing when i plugged it into my HDD box nothing was wrong i could see every folders and everything. But when i put it back into my Computer it seems like it cant boot it up. I dont know what it is i can see it in the bios and all but when i try to set the boot mark in it in some settings outside of the bios ( highpoint bios and something like that ) by pressing ctrl + h i cant see it there which means it cant be booted from.