Windows 10: Laptop Hardware (?) problems

One of my machines is a HP probook 6550b. This has done well over many years use.
Recently it has started running the fan at a higher speed than normal - although the heat from the exit is only very mildly warm - therefore I do not think it to be a heat issue. Yes I have looked at and cleaned the fan area.

The big pain is that after a period of time, (for no reason) if the laptop is doing a task it suddenly stops. Instant total black out, no BSOD.
Battery is OK, and charged so even if the main power supply is possibly intermittent it should still continue.

Here is the how long is a piece of string question !!! What are the possibilities of hard drive failure? I would add that the machine will immediately restart as if nothing had happened.
Your thoughts and suggestions very much appreciated.
Thanks in advance

EDIT
sorry, should have mentioned that this Laptop runs W10...64 bit
Has an intel i5 processor, and 4Gb ram.
It is an intermittent happening - might occur say 15 mins after startup or possibly several hours after.
Have re seated the hard drive and memory just before this post.

:)

 

Laptop Hardware Concerns

Its Dell Laptop, it is good to contact Dell for better help. This is a Hardware problem.

 

start menu stopped working

Cannot get start menu to pop up. Worked till yesterday, now won't. Turned off computer and back on - still won't work

 

See if the Windows Event Viewer shows a Power State Failure...

 

Thanks dmholt57

Running the machine now - hopefully it will fail during the 'fall' update - will then see what event viewer has to say, and report back

 

Not so sure 'Failing' is a hopeful outcome... *chuckle

 

Would you believe it!

Since the original post (at which stage three attempts at installing the latest W10 update had failed) - the Laptop has nearly completed my latest attempt without interruption.*Shock
Wonder if the re seating did the trick for the moment.