Answer

Crucial makes finding the right upgrade easy. We offer two ways to find the right memory — our System Scanner tool and our Memory Advisor™ tool.

Our System Scanner tool automatically scans your system to tell you about your current memory configuration and recommend compatible upgrades for your specific system.

Or, use our award-winning Memory Advisor tool, where we've compiled all the information you need into one easy-to-use, searchable database. Our Memory Advisor is the most complete tool of its kind, with more than 250,000 solutions for over 50,000 different computers, printers, servers, and more. All you have to do is tell us what system you have, and our Memory Advisor tells you what upgrades will work for you. And we guarantee the memory you buy through the Memory Advisor will be 100 percent compatible with your system, or we'll refund the price of the incompatible module.

Answer

The maximum amount of memory that your system can use is actually limited in two ways — not only is there a maximum amount of memory that your computer motherboard can accept, there is also a maximum amount of memory that your operating system (OS) can accept.

For instance, when you install 4GB of memory in a 32-bit Windows system (the most common version; 64-bit systems are typically used only by high-end users), your system will see (and utilize) only 3GB or 3.5GB. Is the problem bad memory?

Relax, there isn't a problem with the memory. Windows allows for 4GB of memory to be addressed, but this isn't 100 percent the same as having 4GB of physical memory.

What happens is that some of the addressable memory (regardless of how much you have physically installed) is reserved for use by page files or by some of the devices that you are using, such as a graphics card, PCI card, integrated network connections, etc., so it's unavailable for use as normal main memory.

The amount of memory needed for these devices is calculated by your system at startup; if you haven't maxed out the memory in your system, it's invisible to you, and all your physical memory (the RAM that's installed) is available for use. However if you've maxed out the DRAM in your system, this amount will be deducted from your physical memory, so you can't use 100% of your DRAM.

The maximum memory limitation varies by operating system; for instance, the 4GB memory limitation doesn't exist in 64-bit versions of Windows.

Memory maximums for current Microsoft® Windows OSs include:

Windows Vista (32 bit)

• Ultimate: 4 GB
• Enterprise: 4 GB
• Business: 4 GB
• Home Premium: 4 GB
• Home Basic: 4 GB
• Starter: 1 GB

Windows XP (32 bit)

• Professional: 4 GB
• Home: 4 GB
• Starter Edition: 512 MB

Windows Server 2003 (32 bit)

• Datacenter SP2: 128 GB
• Enterprise SP2: 64 GB
• Standard SP1: 4 GB*
• Datacenter R2: 128 GB
• Enterprise R2: 64 GB
• Standard R2: 4 GB*
• Web Edition: 4 GB*
• Small Business Edition: 4 GB*

* Certain Microsoft server operating systems can support over 4GB of memory via Physical Address Extension (PAE). Please refer to Microsoft knowledgebase article located here for more information.

Windows Server 2008 (32 bit)

• Datacenter: 64 GB
• Enterprise: 64 GB
• Standard: 4 GB
• Web Server: 4 GB

Windows Vista (64 bit)

• Ultimate: 128 GB
• Enterprise: 128 GB
• Business: 128 GB
• Home Premium: 16 GB
• Home Basic: 8 GB

Windows XP (64 bit)

• Professional: 128 GB
• Windows Server 2003 (64 bit)
• Datacenter SP2: 2 TB
• Enterprise SP2: 2 TB
• Standard SP1: 32 GB
• Datacenter R2: 1 TB
• Enterprise R2: 1 TB
• Standard R2: 32 GB
• Small Business Edition: 128 GB

Windows Server 2008 (64 bit)

• Datacenter: 2 TB
• Enterprise: 2 TB
• Standard: 32 GB
• Web Server: 32 GB

Windows 7 (64 bit)

• Windows 7 Ultimate: 192 GB
• Windows 7 Enterprise: 192 GB
• Windows 7 Professional: 192 GB
• Windows 7 Home Premium: 16 GB
• Windows 7 Home Basic: 8 GB
• Windows 7 Starter: 2 GB

Answer

What is my computer model?

Make and model. It's easy if you're talking about your car — not so easy when you are talking about your computer. Sure, you know if you've got a desktop or laptop. And you know the manufacturer. But beyond that, model specifics can get confusing. When finding a compatible memory upgrade, knowing your exact model is important — here is how to figure it out.

Are you upgrading the computer you are working on right now?
That's easy. Use the Crucial System Scanner. This downloadable tool determines the memory in your computer and tells you what your computer needs. Don't worry — no spyware or anything like that. The tool just looks at the technical, boring details of your system motherboard.

Start here.

How does it work? Watch this video.

Are you upgrading a different computer?
You can use the Crucial Memory Advisor. In just three clicks, we can tell you what memory upgrades are available for your system. But, you will need to know the make and exact model.

If you're using a Windows-based system, the model will be specified on the label, a small sticker on the back or

side of your desktop system, or the bottom of your laptop.

If you can't find the label, you can find model information this way.

Start ==> My Computer ==> Right click ==> Properties.

Or for more detailed info go here:

Start ==> Run ==> Dxdiag

You'll see "System Model" — that is the specific model of your computer and the information you'll need to use the Crucial Memory Advisor.

On a Mac system, you can find your system by first going to the Apple icon on the top left.

About this Mac ==> More info

Once you've determined the model, use the dropdown menu on the Crucial Memory Advisor to determine compatible upgrades.

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For more information on DRAM, go to our Knowledge Base library or our news and information page. For additional information on Crucial DRAM products, go to our product pages or support center.  We have lots of videos for you to watch on our YouTube Channel. And if you’re ready to take the plunge, use the Crucial Memory Advisor or the Crucial System Scanner.