error. code. 4MEM/9/40000000:OX82d38c98

It's teling you that one or more of your RAM chips is either bad, or loose.

Check them out . . . could be one is loose.

It's just a matter of trying again, and testing.

msaidurrahman wrote:

How should i confirm one is loose? i have a 4gb+4gb

Simple, remove and reseat all the RAM.

msaidurrahman wrote:

should My mac sopport 16gb ram?

Considering you haven't told us which iMac you own we cannot say for sure. If you don't know look in theTech Specs and input your serial number. Then once you know which year iMac you own navigate to OWC's web site and it will advise how much RAM your computer may accommodate.