Hi Kevin,
Looks like you really need to get hold of an XP install CD as symptom could be caused either hardware (hard drive) or corrupt Windows file. If it is hardware failure, I believe you have a malfunctioning HDD since this is a victim of a fall. The message that you see could just be a result of this malfunction and a fresh install of XP is needed. On the other hand if this is just a corrupt Windows file (HDD is still good and working), you then have to copy the NTFS.SYS into your laptop (see this:
http://support.microsoft.com/kb/822800)