OS MOJAVE CAN BE ONLY INSTALLED ON 10.8 OT LATER ? HIGH SIERRA WANT LET ME

Here are the hardware requirements:

These Mac models are

compatible with macOS Mojave:

• MacBook (Early 2015 or newer)
• MacBook Air (Mid 2012 or newer)
• MacBook Pro (Mid 2012 or newer)
• Mac mini (Late 2012 or newer)
• iMac (Late 2012 or newer)
• iMac Pro (2017)
• Mac Pro (Late 2013; Mid 2010 and Mid 2012 models with recommended Metal-capable graphics cards)

Your mid 2010 iMac clearly is not on the list of supported models/years.

Here are the requirements for installing Mojave: macOS Mojave - Technical Specifications

If your computer does not meet these requirements you can not install Mojave. Old non-supported hardware; no drivers; different hardware; ...

vivah61 wrote:

Mine is Mid 2010 but iMac .Oh gezz....What the solution ? upgrade hardware ? Thank You

If you want/need to run Mojave the only option you have is a newer computer.

The only “upgrade” you can do to the hardware that will allow anything higher than High Sierra to run is to buy a new Mac.

Which exact Mac do you have?

Apple Logo at top left, About this Mac...

Yep, a newer Mac is the only way to go higher. & the new ones won't run Mojave, likely Monterey or newer only.

But you could buy a used iMa that is newer tan your 2010 model...

Used & Refurbished iMacs, iMac Desktops | Mac of All Trades

Understood, take care my friend! :)