Causes are old CD drives, smudges on lens or media so take action to correct that.
And let's be clear there is no supported downgrade path. You can install XP from scratch but it's a bad idea with just a few more months till the end.
Bob
Hey guys,
I have a laptop HP530.First OS that it had is Windows XP.Then I upgrade it to Windows 7 but I want to downgrade it back to Windows XP.I put the CD and it waits a little an the it boots normally to Windows 7.I change the bios and then I restarted and the same.It boots normally to Windows 7.Please help me!

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