Thanks everyone for help. I again asked Acer and the guy tells me that they never solder their CPU to motherboard, and he's told me this
As per the records, I see that the following i5 processors might suit this unit.
• Intel Core i5-540M (2.53 GHz)
• Intel Core i5-430M (2.26 GHz)
However, we are not sure whether this works with this computer. As the manufacturer, Acer does not recommend to alter the hardware/software components.
Since this cause compatibility issues.
What do you make of this?