The removal probably removed a boot maanger. You can boot your XP CD and use FIXBOOT.
Reference -> http://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/winxppro/proddocs/bootcons_fixboot.asp
Retest and then consider FIXMBR
Usually that gets it, look at BOOTCFG if need be.
i have installed windows XP and linux mandrake on the same machine and i when i removed the Linux installed hard drive from the machine and 1 and 0 is displaying in diferent sequences and displays an error message saying "unable to boot". what do u think should i do. i dont want to format and re install windows agin.
thanx for the help in advance.