smwdm. sys - related to sound cards. If the error is always in this driver, it's a good clue; if you have a plug-in sound card, unplug it and try rebooting. You can also try reseating all pluggable chips and cards - rock/wiggle the chips and unplug/re-insert the cards. Keep yourself grounded to avoid static!. The sound card or MB might have gone south. Another possibility is heat; built-up dust can reduce heat removal, as can a failed CPU or system fan. Over-clocking is another possible source of problems. Less likely is a power supply on the verge of failing; usually, they simply fail, but if it is marginal voltage, it might cause problems.
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