Helping people with computers... one answer at a time.
If you don't have your Windows installation CD there are still a few things you can do. If you have an image of your CD, you may be able to do more.
I have no CD - how do I get at Windows XP setup?
I discussed in a prior article what to do if you have no installation CD for Windows XP. But now once you've found your CD image - where's the setup?
What you need will depend on what you're attempting to do.
If you want to make a change to your system configuration - perhaps adding an accessory that you neglected at the original setup - then the place to go is not setup, but the control panel:
That will bring up the dialog that's extremely similar to setup in which you can select the optional Windows components to add or remove.
If you're looking to reinstall system files because you suspect corruption what you really need is the System File Checker. This utility validates that all of Windows' system files are correct and fixes those that are not:
sfc may ask for your installation CD-ROM. (See this article if you don't have one.)
Finally, if you really, honestly and truly want to re-install windows, the first step would be to run your installation CD. If you don't have one, you may have an image of the CD on your hard disk. In the I386 directory are two files:
WARNING: character.exe and winnt32.exe are the "start-from-scratch", "do-it-all-over-setup" programs. Use them only if you want a complete re-install of Windows - possibly losing any prior custom configuration changes you made, depending on whether setup is installing on top of and can understand a prior installation.