If you're using Windows XP Professional or XP Home Edition, you likely know about the Windows Update feature. But have you considered what you would do if you needed to reinstall Windows? To avoid losing your updates, you need to customize the Windows Update settings.
Right-click My Computer, select Properties, and click the Automatic Updates tab. Select the Notify me before downloading any updates and notify me again before installing them on my computer option.
When you download the update file or files, the file or files will be in the hidden folder C:\program files\windows update\cabs\folder-name\file_with_update.exe. The file called file_with_update.exe will have the update date. For example, my last update is in C:\program files\windows update\cabs\4715\250501_x86.exe and has the date 07/02/01. You can run file_with_update.exe and manually install the update. You can then copy the file in case you need to use it again (e.g., after a Windows reinstallation).