windows 7 only sees 3gb ram when 4gb installed

[ralphf]

I recently upgraded my hp pavillion dv6000 laptop from Vista to Windows 7. I'm up and running in 64 bit mode but Windows 7 is not making 4gb of ram available, only 2.99 gb. I noticed this when I started getting warning messages that I was low on memory. I checked basic info and it showed 4gb installed but only 2.99 gb used. I thought 64 bit os would see the entire 4 gb of ram.I checked my bios and there is not much to change. Bios shows total memory of 4096mb with version F.2e of bios installed. I checked the performance tab of task manager and it shows the following physical memory: total 3062, cached 1454, available 1639 and free 272. At desktop I'm using 1.38 gb so not much more ram can be made available. Can someone explain what these ram numbers mean? Does anyone have any ideas why this is happening in a 64 bit system. Thanks in advance for your help.

Ralph

[ruirib]

I am not sure what you mean by running ib 64 bit mode. Does that mean you are running a 64 bit Windows 7 version?

Anyway, even with 7 x64 bits, it really depends on your motherboard / chipset too. Some chipsets aren't able to handle more than 4 GB of RAM, so even using Windows 7 x64, you may not access all that memory. It would not be the first situation of that type we see here.

That said, I don't know if it is your case. It may also depend on the amount of memory your video card is using, if that memory is taken from the system RAM, which sometimes happens with entry level systems.

[Medico]

Also you say you "upgraded" Vista to Win 7. Do you mean you Custom (Clean) install Win 7 64 Bit over the Vista 32 Bit? Changing from 32 Bit to 64 Bit does require a Custom Install.

Yes, unless you have a separate Video card, an integrated card may use system Ram. Some systems do not have faster video ram.

[satrow]

You might need to update the BIOS to make all the RAM usable by Windows x64.

[ralphf]

Thanks for all the quick replies. I am running win 7 64 bit having done a clean install. But I need to let you know that this upgrade is not supported by HP since it's an older machine(2008). I upgraded to the latest bios before I upgraded to windows 7 and was told that this bios will support 4gb. I just can't understand why the bios recognizes 4gb of ram and windows doesn't. My internal intel video processor is using 128mb of ram but I did change this to 64mb but that didn't change a thing. Do you think if I went back and installed Vista 64 bit I'd have 4gb of ram available?

[ruirib]

Most likely Windows recognizes the 4GB, but for some reason cannot use the 4 GB. Check Control Panel->System (or System and Security -> System) to see how much memory Windows detects.

I don't think it would be any different with Vista, no.

[RussB]

This may be more information than you want but it explains it all in detail.
blogs.technet.com/b/markrussinovich/archive/2008/07/21/3092070.aspx

[bbearren]

If the BIOS is showing 4096MB and the performance tab of task manager is showing 3062MB, that probably means that the BIOS is allocating 1034MB to the chipset before Windows boots. You're talking about a machine that is over 4 years old, and even the latest available BIOS can't be too much younger than that.

Control Panel > System and Security > System probably sh0ws 4.0 GB (2.99 usable).