Hi,
What have you recently installed? Please incude make, model number,etc.
Recovering XP using the Recovery Console (Line 333) right hand side
http://www.kellys-korner-xp.com/xp_tweaks.htm
In Recovery Console, change to the C:\Windows folder.
Type: cd sytem32\config , and then press ENTER.
Type: dir system , and then press ENTER.
Depending on your error message, use as follows:
Next type: ren software software.bak and then press ENTER.
or:
type ren system system.bak and then press ENTER.
Next type:
copy c:\windows\repair\software , and then press ENTER.
or:
copy c:\windows\repair\system , and then press ENTER.
Exit, reboot.
NOTE : If the message that you received referred to the software file,
replace "system" with "software" in the preceding command.
For example, you would type ren software software.bak (instead of ren system
system.bak ), and then press ENTER.
More info here:
http://www.kellys-korner-xp.com/xp_sys32.htm