Using the Windows XP Command Prompt
Here are the instructions from the Help and Support files on how to make a computer running Windows XP start up at the Command Prompt:
"To start your computer at a command prompt"
"Print these instructions before continuing. They will not be available after you shut your computer down in step 2. Click Start, click Shut Down, and then, in the drop-down list, click Shut down. In the Shut Down Windows dialog box, click Restart, and then click OK. When you see the message Please select the operating system to start, press F8. Use the arrow keys to highlight Safe Mode with Command Prompt, and then press ENTER. If you have a dual-boot or multiple-boot system, choose the installation that you need to access using the arrow keys, and then press ENTER."
However, although the above information is still the only information available in its Help and Support files, this method doesn't work in versions of Windows XP starting from Windows XP SP2 (containing Service Pack 2). You have to click Start => Turn Off Computer => Restart. No "Please select the operating system to start" message comes up. You are just told that the computer is shutting down. The computer then restarts. All you have to do is press the F8 key after the startup screen has completed the memory count to bring up the following list of startup options.
These are the selectable options available in every version of Windows XP:
Safe Mode with Networking
Safe Mode with Command Prompt
Read the Q&A on this site called My Windows XP Pro computer with a USB keyboard won't boot into Safe Mode if pressing the F8 key won't bring up the boot menu containing these options.
Enable Boot Logging
Enable VGA mode [loads the standard VGA video card device driver]
Last Known Good Configuration (your most recent settings that worked)
Directory Services Restore Mode (Windows domain controllers only)
Debugging Mode [For expert use only]
Disable automatic restart on system failure [Available with Windows XP SP2. Selecting this option should prevent continuous rebooting]
Start Windows Normally
Return to OS Choices Menu.
To open the command prompt from within Windows XP, click on Start => Programs => Accessories => Command Prompt or just enter cmd in the Start => Run box. This opens a DOS-like black window the likes of which you might have thought was lost to Windows XP.
Windows XP only runs MS DOS if you try to run an MS DOS program from its command-line console (Start => Run => enter cmd). It won't run MS DOS from a startup floppy disk even if it is using the FAT32 file system that most Windows 9.x systems use.
It doesn't matter how many passwords are set on a Windows 95/98/Me system, you can bypass them all by booting the system with a startup floppy disk. The same is true with Windows XP if it is using the FAT32 system, which is useless from a security point of view.
To secure the system, Windows XP should use the NTFS system, even though it has recently been established that it is possible, due to an unplugged loophole, to gain access to a Windows XP system merely by booting it by using a Windows 2000 CD.
If you upgrade the system from Windows 98/Me to Windows XP, you will be asked if you want to convert from FAT32 to the NTFS file system. If you convert to NTFS, third-party utilities, such as disk defragmenters, that are designed to be used on a FAT32 system, will no longer function, but the system will be far more secure. Once you convert, there is no way to revert to using FAT32 by reinstalling Windows XP. You would have to reformat the boot drive, install Windows 98/Me, upgrade it to Windows XP, and refuse the option to install the NTFS file system.
If you install Windows XP from scratch, you can choose which file system to use. Just remember that if you want to transfer files to a Windows 95/98/Me system you have to use FAT32, because you can't use an NTFS floppy disk on a FAT32 system, and the two files systems can't read or write to one another's drives.
If you boot to a Windows XP system using NTFS with an MS DOS startup floppy disk, Windows XP doesn't have MS DOS, so you won't be able to access the hard disk drive. So how are you going to attempt to recover a failed system?
If the boot menu can be accessed by pressing the F8 key at startup, an XP system offers a range of boot choices, some of which are three modes of Safe Mode - with a graphical Windows interface, the same with networking drivers installed, or as a command prompt.
If you can start the computer in a Safe Mode, if you know how, you can access most of the tools that can aid in solving problems.
For example, XP will name a corrupt system file that is the source of a problem. You will then just have to copy it from the XP CD to its location on the hard drive in a Safe Mode.
The Enable VGA Mode (probably provided for overt video-diagnostics purposes) installs the VGA 640X480X16 video driver, which all of the Safe Mode options also install.
Last Known Good Configuration
The easiest way to recover the system would be to try running the Last Known Good Configuration option. But this feature will not work if there is file corruption involved, because the configuration refers to backdating the Windows Registry, which has no influence on the condition of the files that are installed.