There are many reasons why your PC might slow down, but few have quite such a dramatic effect as running short on available RAM.

If this happens to you then you'll notice the hard drive begin to thrash, as Windows writes blocks of memory to your paging file.

Before long your system's performance could slow to a crawl. And if you're really short on memory then some apps may not be able to cope, crashing or displaying odd error messages, and your system will become virtually unusable.

It pays to keep an occasional eye on how your RAM is being used, then, to identify ways in which it's being wasted, and free up the memory for more important things. It's a surprisingly straightforward process, and just a few minutes of exploration can make a real difference to your PCs performance.

Remove RAM-hungry applications

The best way to begin to free up RAM is to understand how your system is using it right now, and the best tool for doing that is Process Hacker.

This powerful free tool comes in a compact 1.4MB ZIP file, runs on all versions of Windows from XP SP2 upwards, and doesn't even require installation: just unzip it, browse to the appropriate folder (x86 for 32-bit Windows, x64 for 64-bit), launch ProcessHacker.exe and you're ready to go.

The Process Hacker "Processes" tab will immediately tell you more about the processes running on your PC. We'll need to make sure it's displaying the right information, though.

Right-click on the Name column, and make sure the Active Columns list includes Name, Pvt. Memory and Description at a minimum (having other values as well isn't a problem). If you don't see one or more of these, find and select them in the Inactive Columns list, and click OK to add them to the display.

We added "Pvt. Memory" (Private Memory) here because it tells us the RAM that each process alone is using, memory that isn't in use by anything else - it's probably the best single indicator of how RAM hungry an app might be. And to see what that means, click the "Pvt. Memory" column header twice to sort your list of running processes by memory use, with the highest value at the top.

Now it's just a simple matter of scanning down the list and looking for programs that you don't really need. Such as? We tried this on a demo PC, to find out.

System tray

EATING RAM: Do you really need all those system tray programs, running in the background?

Top of our RAM-use list were Internet Explorer and Outlook. They both have to stay, but if we wanted to run a memory-hungry program, like a game, it's a good reminder that we'd benefit from closing those first.

Third from the top, consuming more than 90MB was "MSWinext.exe", which the Description column told us was the Bing Bar, bundled with Windows Live Essentials. Browser toolbars can be real memory hogs; if you have any that you can do without then uninstall them for a quick RAM boost.

Our test PC also had a SVCHost.exe process, consuming 72MB. You'll see many SVCHosts, as they're used to support Windows Services, but double-clicking this one and selecting the Services tab told us what was grabbing our RAM here: Windows Defender.

If you have a full antivirus/antispyware package already and you don't use Windows Defender as a backup, then there's no point having it running in the background. Launch the program, click Tools > Options > Administrator, clear the "Use this program" and click Save. When you need reboot Defender won't be relaunched, and you'll have freed up more RAM.

And further down the list we found a host of smaller programs that were loaded every time our PC started, none of which were essential.

Startup options

DON'T LOAD: Most startup programs have a setting you can use to ask them not to load at boot time

There was uTorrent, for instance, which doesn't have to be loaded every time your PC boots. We launched the program, clicked Options, and cleared "Start uTorrent on system startup" to prevent this happening in future.

The Nero BackItUp Agent had installed as a part of our Nero MultiMedia Suite 10, even though we weren't using the backup program. Right-clicking its system tray icon and clearing Launch At Startup would free up more RAM at the next reboot.

And there was a LightScribe process running in the background, too, even though we never, ever used it to burn labels on our discs. But this was just as easy to fix. Right-clicking the LightScribe system tray icon, selecting Open LightScribe Control Panel and clearing the "Run this program when I log on to Windows" option would prevent the process hassling us in future.

Your PC will have different programs and processes, of course, but the principles are the same: find programs that are running unnecessarily, and either uninstall them completely if they're surplus to requirements, or change their settings to prevent them launching at boot time if you're happy to launch them manually, when required.

MSConfig

FREE UP MORE RAM: MSConfig will disable RAM-hogging startup programs at a click

Sometimes this can be a challenge, as a particular program won't provide an option to prevent it loading at boot time, but you can always tweak this manually. Launch the Windows System Configuration tool (msconfig.exe), clear the boxes next to programs you don't want to launch when you need reboot, and, well, that's it: more RAM freed up next time.

Be careful, though - don't get too carried away with closing programs down. Some may be essential to apps you're running, or at least perform very useful functionality: a startup program that installs security updates when they appear, for instance.

So if you're completely sure a program is unnecessary, then by all means get rid of it, but if you're at all uncertain about what it's doing, then leave the application alone. Freeing up a few megabytes isn't worth the risk of breaking your entire PC.

More ideas to free up RAM

Removing your PCs major resource hogs will have the greatest effect on performance, but there are a few other ideas you can apply to free up a little more memory.

Review any extensions you've added to your browsers, for instance. Some of these can use a significant amount of RAM, so if you don't use them any more, then ditch them now. Click Tools > Manage Add-Ons in IE, or Tools > Addons in Firefox to find out more.

It's a similar story in some applications. Microsoft Office add-ins, say, will use RAM and slow down application boot times. Again, take a look at what you've got installed (File > Options > Add-Ins in Outlook 2010), and remove anything you know you don't need.

Explorer

RAM-HUNGRY: Explorer windows, especially large icon views, consume lots of RAM

Be careful in how you use Explorer, too. Every new Explorer window we open on our Windows 7 system consumes an extra 5MB of RAM at a minimum, for example.

And if we turn on the extra large icons to browse some digital photos, then that rises to around 40MB extra (again, for every window with that setting). So keep on opening Explorer windows as necessary, but when you've finished, close them down and recover that RAM.

Disabling non-essential Windows services can also reduce the drain on your RAM, although here you have to be particularly cautious: just one mistake and your PC could crash immediately. Read Streamline Windows services to find out more.

And if your PC is on 24-7, then one of the simplest ideas of all is just to reboot it occasionally. Some processes will grab memory when required, but not release it all later, and so over time they'll use more and more RAM: a reboot will free all this up again, leaving the maximum possible amount of RAM free for your applications.

Apply these rules and it's surprising how much RAM you can save, but keep in mind that surplus processes and programs will creep back again, reinstalling memory-hogging modules, and often without asking your permission. So use Process Hacker to keep an eye on your running processes, just once every week or so, remove anything unnecessary, and you'll ensure your PC is always running at its optimum performance.

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Liked this? Then check out 15 Task Manager tips for a faster PC

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