Last night for some reason my pc shut down. (Compaq Presario 6000 series) No previous form over several years. Now it won't start correctly at all. I get the screen that offers normal start/safe mode etc but usually after about 15 secs the sequence reverts to the beginning again. Very occasionally I can get as far as logging in, but then, again,the start sequence fails back to the beginning. No chance to get as far as accessing system restore or to run any checking software. Hard drive failure? Battery failure? I'm lost, so help please.
Thank you Phono. Now for the odd bit. I was duly bemused by all the possibilities your links offered, so thought I would have another go at starting my pc. Response varied from almost nothing, just the Compaq splash screen, to most often the 'F12' screen with no option working correctly. Opened side of case, poked HDD connection, gave case a mild thump, tried again and it worked.
When it did come to life, selecting my log in caused it to crash again. Next time it came up I tried Guest account and that was ok! (wipe forehead). After leting McAfee do its auto updates tried log off change user and IT WORKED!! Microsoft came up with its usual offer to report the problem which it attributed to an 'unnown driver' error.
Problem is pretty much solved, but do you think it is time for a new HDD?
It may just have been a loose data or power cable or even a poorly seated card, I would power it off, open up and check that all cables and cards are correctly seated by using firm but gentle pressure to ensure they are fully in place, restart and see how things go.
If you suspect the HD is failing you should immediately get a replacement and install it before you lose all your data, the drive manufacturer should have software to enable you to prep and install a new drive, also diagnostic software to check the original drive.