What causes the inability to enter Windows XP?

Q: The system is Windows XP with SP2, prompting at startup "Windows could not start because the following file is missing: \\system32\\driverstfs.sys", and cannot enter the system. How to solve?
A: You can enter the recovery console and run the following commands in sequence: (assuming Windows XP is installed on the C drive)
cd system32
ren ntkrnlpa.exe ntkrnlpa.old
ren ntoskrnl .exe ntoskrnl.old
cd "c:\\windows\\driver cache\\i386"
expand sp2.cab -F:ntkrpamp.exe c:\\windows\\system32
expand sp2.cab -F: Ntkrnlmp.exe c:\\windows\\system32
cd c:\\windows\\system32
ren ntkrpamp.exe ntkrnlpa.exe
ren ntkrnlmp.exe ntoskrnl.exe
exit
Tip: If Previously deleted sp2.cab, you can run "ldcopy;xcopy F:\\i386\\SP2.cab c:\\windows\\driver cache\\i386\\” (assuming the F drive is an optical drive).