DVD drive on win 7 system no longer working after I accidentally pushed the on/off button on the system unit while win 7 booting. Device manager said the dvd is working fine initially & the driver is up to date but after device manager did the test it came back not installed & now the dvd drive doesn't show up in device manager or even in explorer. When shut down blue screen said driver power state failure & info if a new hardware had been recently installed, Confusing for me. Tried going back to an earlier restore point but made no difference. Would really appreciate some help plse.
Interesting issue, if it doesn't work in another system, I would advise to attempt to update the firmware of the DVD drive itself.
Determine the make and model of the drive and look on the manufacturers website for a firmware update tool.
There's a small but feasible chance that cutting power whilst the DVD drive was running its own start up procedure has caused it to bug out.
As I say, though, try it in another system first.
Update: Your edit is either further evidence to support some issue with the drives firmware, or may indicate an issue with your power supply (or damage to the drives power regulation circuits).