Hyper-threading is a technology supported by the Intel processors in which a single CPU (Central Processing Unit) can behave like multiple CPUs. The benefit of using the CPU in this way is that it allows different applications to use the resources separately thereby making optimum use of the CPU. However, problems do occur when you use the hyper threading in a system on which you have installed both Windows XP Service Pack 2 and Rollup 1 for Windows XP. In such situations, the system is unable to start. But you can recover the system by renaming the overwritten system files. If that does not solve the problem, then the best way is to use a third-party NTFS data recovery software.

Consider a scenario in which you have an NTFS-based Windows XP Service Pack 2 system, which is unable to start. The following error message is getting displayed: “Windows could not start because the following file is missing: \system32\drivers\ntfs.sys”

Cause: This problem happens when all of the following conditions hold good: • Windows XP Service Pack 2 is already installed in your computer system. • You have installed Windows XP SP1 rollup in your system. • After that, you have either enabled hyper-threading or added another processor to your computer. The problem appears because you have installed the '826939 Update Rollup 1 for Windows XP' after installing Windows XP SP2.

Resolution: This problem can be resolved using the following steps: • Adjust the BIOS settings so as to boot the system from a bootable CD. • Start the computer by inserting the Windows XP Setup CD in the CD drive. • Press the 'R' key, when the 'Welcome to Setup' screen is displayed, to enter the Recovery Console. • At the command prompt of Recovery Console, enter the following commands followed by the 'Enter' key after every command: 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 • Enter 'Exit' to quit Recovery Console and restart the computer. It should start properly now after addressing the problem.

If the problem does not get away, then the data in the computer becomes inaccessible and, thus, insecure. In such cases, I would recommend you to use a third-party NTFS partition recovery software to recover the trapped data. Using these read-only tools, you can make sure that the NTFS recovery is safe and secure.

Of the very few NTFS file recovery tools, Stellar Phoenix NTFS Data Recovery ranks on the top of the chart. With the capability to extract data from NTFS and NTFS5 file systems, this NTFS data recovery utility is compatible with Windows 7, Vista, Server 2003, XP, and 2000.