You just need to rewrite the boot loader. If you find your way to the XP RECOVERY CONSOLE, then FIXMBR will overwrite it.
In closing, a proper XP install does NOT use the old DOS format command. Those who don't learn the new ways tend to suffer a little.
Bob
I have an HP 6635 Pavilion running Win 98 and Linux I want to upgrade it to XP. I formatted the drive. But Linux still comes up when the machine boots up. The linux has errors and that does not boot up properly
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