Start with a blank, formatted floppy disk. It may seem counterintuitive, but this disk shouldn’t be bootable. If you need to format a floppy, simply insert the disk into its drive, double-click My Computer, right-click the floppy drive icon, select Format, and then click Start.

Next, open your C: drive in Windows Explorer. If Explorer displays a warning, click Show the contents of this folder. To display the particular files you need, select Tools, Folder Options, then click the View tab. Make sure Show hidden files and folders is selected, and uncheck Hide protected operating system files (Recommended). At the warning, click Yes, then OK.

Copy the files boot.ini, ntdetect.com, and ntldr to your floppy. Remove the disk, open the write-protect switch in its bottom-left corner, and label the floppy “Boot Disk.” Return to the Folder Options dialog box and recheck Hide protected operating system files and folders (Recommended).

Place this floppy in the drive and reboot your system. Your PC will bypass the basic boot files on your hard drive, but it will otherwise load Windows normally.