My idea is
computer storage or degrading computer components
A life inside the confining dark
Computer enclosures are dark inside
Their work unseen, but try to hark
you do not see them working
Hark to what they say, get steady
For storage, the OS will warn you of running out of space. For computer components, they often give warning when failing. Disk drives overheat, get loud, or stop writing. Flash storage generally becomes readable but not writable. Fans will start working less optimally... etc.
Go ahead and free one already
Storage: free memory or drive space. When resources are no longer being used, it is often referred to as "freeing" or "releasing" the CPU/RAM/etc. Components: free the broken part
From my experience I can tell
Knowing about computers, or the computer knowing its own components
I'm very close to my defeat
Storage: defeat is a completely filled drive. Failing components: defeat is the end of the part's lifespan
Maybe a clever mind can help
a technician, or someone who can work on computers
Which one is it I urgently need?
Storage: what region of disk space or what files to delete... or which between disk/RAM. Components: which part needs to be replaced.
Regarding hint:
I suppose you must use the computer to find if you are out of space, and the computer can also run diagnostics on your hardware. But it seems like awkward phrasing that it was suggested to "use a computer to solve this". Alternatively, you may need to research all this information... but it was stated "the computer" and not "Google".