Lost 4Gb memory

Hi I have been using my computer for quite a while now running Windows 7 Professional 64 bit edition with 12GB memory

All ahs been ok for quite a time but after a series of unexplained crashes I decided to format my C drive and reinstall windows as a fresh install

But now I have windows running again Windows only reports 8GB memory and I know there is 12GB installed. CPUZ says there are 12GB but windows only see 8GB

I have not changed anything just reinstalled windows 7

The only thing I did wrong when I reinstalled Windows I mistakenly installed the 32 Bit version and I saw there was only 4Gb of memory available, and I understand the 32bit version can only use 4Gb.

I then formatted the drive again and installed the 64Bit version but now windows can only see 8GB, so there is 4GB missing

Can someone help please

Post a screenshot of Memory tab in Resource Monitor. Screenshots and Files - Upload and Post in Seven Forums

Try loading defaults in BIOS.
Take out and reseat the memory modules
Run a memtest for 6-8 passes or overnight RAM - Test with Memtest86+

It shouldn't matter if you reinstalled 64bit.

Ok thank you I am not at my computer at the moment but when I am I will look at what you have suggested.

I find it strange that until I reinstalled window I had no problems with the memory, this only happened after I installed the 32 bit version of windows

I will check and post back

Thank you

GokAy said:

Post a screenshot of Memory tab in Resource Monitor. Screenshots and Files - Upload and Post in Seven Forums

Try loading defaults in BIOS.
Take out and reseat the memory modules
Run a memtest for 6-8 passes or overnight RAM - Test with Memtest86+

It shouldn't matter if you reinstalled 64bit.

Hi GoKAy thank you for the advice I loaded all default settings in BIOS and rebooted and I still had the same problem.

So I removed the two memory modules nearest the CPU and then rebooted and it still showed at 8GB so I removed the next two modules and rebooted and then it showed 4GB memory installed so I then replaced the 4 modules I had removed and rebooted

I was surprised to see 12GB again just by removing the modules and replacing them

I do know understand why this happened as the PC is under my desk and it was not moved or opened when this problem happened its never moved for at least a year

So why did I have to remove and replace the memory?

I wouldn't know the exact workings :)

I believe you can only have 1 timing setting in BIOS even though the 2 RAM sets have different specs. Perhaps by removing the 2 you made those settings auto switch to more compatible numbers. Just a speculation of course.

Maybe someone experienced can shed some light.

sam49 said:

Ok thank you I am not at my computer at the moment but when I am I will look at what you have suggested.

I find it strange that until I reinstalled window I had no problems with the memory, this only happened after I installed the 32 bit version of windows

I will check and post back

Thank you

Are you running 32bit Windows? Or was that a typo?

Windows 32 bit can't utilize more than 4GB of RAM. You need to be running Windows x64.

Starting with Vista SP1, Windows now 'reports all of the installed RAM', instead of only what is available to the OS.

However, nothing has changed as far as what is available to the OS. As others have stated, with 4GB RAM installed, around 2.5 to 3.6GB will be available, depending on the system.

CountryBumkin said:

sam49 said:

Ok thank you I am not at my computer at the moment but when I am I will look at what you have suggested.

I find it strange that until I reinstalled window I had no problems with the memory, this only happened after I installed the 32 bit version of windows

I will check and post back

Thank you

Are you running 32bit Windows? Or was that a typo?

Only for a while...

sam49 said:

I have not changed anything just reinstalled windows 7

The only thing I did wrong when I reinstalled Windows I mistakenly installed the 32 Bit version and I saw there was only 4Gb of memory available, and I understand the 32bit version can only use 4Gb.

I then formatted the drive again and installed the 64Bit version but now windows can only see 8GB, so there is 4GB missing

It looks like I scored poorly on Reading Comprehension on this test.

Edit: Oh I see now, I was late to the party! :)

He installed 32 bit by mistake and later installed 64bit.

The only thing I did wrong when I reinstalled Windows I mistakenly installed the 32 Bit version and I saw there was only 4Gb of memory available, and I understand the 32bit version can only use 4Gb.

I then formatted the drive again and installed the 64Bit version but now windows can only see 8GB, so there is 4GB missing