HP Laptop Windows 7 mystery ailment

[Andycon]

My HP Pavilion g4 laptop, just a couple years old, has recently become very ill with a host of symptoms. I've scanned with Malwarebytes and Windows Defender with nothing detected.

-Screen goes dim half a second after first startup screen appears. Can't adjust.

-Skips login/password page and goes straight to desktop (I've never had a password but always got this screen and hit 'enter' when starting or opening back up).

-No sound. Hovering over volume icon shows 'The audio service is not running' but Task Manager show Windows stisvc audio 'running'.

-Won't come back from Standby mode. It's humming like it's working hard but completely unresponsive black screen. Can only shut down by holding power button down.

-Firefox slow (but nothing terribly new there)

Otherwise, when fired up works normally (typing on it now). I'm not much of a tech guy but have tried everything I know short of reformatting. I thought I'd just get away from the entire problem whatever it is by upgrading to Windows 10, the download and install took forever and I hit restart and when to sleep. Next morning same old Windows 7, the install apparently failed but there was no message to this extent anywhere. This may have ruined my chances to restore to earlier settings as the only restore points that come up are after 16 March.

I've recently been in the tropics in a hot humid climate for some time but it worked fine there and for a week after. I'm wondering about hardware issues but these varied symptoms seems to point to a virus or software issue.

Help me Malwarebytes forum, you're my only hope!

[garioch7]

Andycon:

Welcome to the Malwarebytes Forums.  If you suspect that your computer is infected, you should post in the Malware Removal Help Forum.  Malware removal is not permitted in any other Forum here.  Please follow the instructions *here* and post a new topic in that Forum.

Good luck and have a great day.

Regards,
-Phil