basically, as far as I understand it..resetting the config data in bios just resets all the irq's etc..so next time you boot everything will have to "fight for" the irq's as they are re-assigned.
it comes in handy sometimes if you install a new card and the card might need a CERTAIN irq that is already being used by another card etc..in that case you can reset the config data "escd"..and it may straighten out the conflict.
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have you tried a new power supply?? when I hear "random lockups"...usually 3 things come to mind
1) need windows reinstall
2) ram
3) power supply issues
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of course heat also but usually heat has a pattern....it runs good on the first boot up of the day...or after its been off a while..but then the heat builds up etc and it starts locking up.
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also...have you looked at th emotherboard to see if it possibly has any bulged capacitors?? if so they culd obviously be the problem.
some info/pics of bulged caps
http://www.feistworks.com/ben/3comfix/ http://www.pcstats.com/articleview.cfm?articleID=195
JP