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It has 12 GB RAM but in Windows 7 ultimate it says that 3.17 GB is usable, Also in task manager is not showing 12 GB physical memory it’s totally 3251 MB. Is it Windows’s problem or others? What is the problem? Thank you
You likely are using a 32-bit version of Windows 7. 32-bit operating systems have a limit of only being able to see 3gb of RAM. You need to switch to a 64-bit version of Windows.