You cannot install WMP10 on top of WMP11. WMP10 has a broken installer:
please don't even try this because you will corrupt files if you do manage
to hack it that way.
Only install WMP10 on top of a system with WMP9 or lower.

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Speaking for myself only.
See http://zachd.com/pss/pss.html for some helpful WMP info.
This posting is provided "AS IS" with no warranties, and confers no rights.
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>> I have downloaded Windows Media Player and have validated my XP Home
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>> download; says it isn't compatible with "this version" -- but that's
>> another kettle of fish altogether. One thing at at time :)