Does your Windows computer seem slow, or does it seem to be running a number of mysterious processes like svchost.exe? If you've looked at your list of running processes in the Windows Task Manager (press Ctrl-Shift-Esc on your keyboard and click the Processes tab), you've probably seen a lot of things that you don't recognize. These can eat up system RAM, which can affect functionality, like how many applications and browser tabs you can have open at once. It's a good idea to check the Processes list regularly for suspicious activity, but if you don't know what you're looking at, it can create needless anxiety. So let's explore what the common processes do and how to manage them correctly.

How Windows uses system RAM

Starting with Windows Vista, Microsoft has gotten very good about managing system memory. When you need RAM for something that requires a lot of it, Windows will intelligently free it up. It's not necessarily a bad thing to have only a few gigabytes of available RAM left. You can see why if you open the Task Manager and click the Performance tab.

Down in the lower left, you can see how much RAM Windows is using for its cache. (In Windows 8.1 and 10, click Memory on the left-hand side.) The cache is a collection of files and running programs that Windows has determined to be important, as in frequently accessed. Putting this stuff in RAM is much faster than retrieving it from a storage device. This cache may overlap with the RAM being used by the program you're running right at that moment, so closing the program may change the size of the cache. Windows will also dump out some of this cache if a program requests a lot of RAM.

Monitoring svchost.exe

Svchost.exe is an umbrella name for a large number of Windows' native processes, and all things being equal, you should never have to worry about it or mess with it. You'll see multiple entries for svchost.exe in the Task Manager, and the group as a whole may take up a lot of RAM. This is normal. But you'll see svchost.exe in the Task Manager constantly, so you may want to know more about what it's doing.

In the Task Manager, click the Processes tab to take a closer look. (In Windows 8.1 and 10, click the Details tab in the Task Manager instead of Processes.) To see what's running within each instance of svchost.exe, just right-click the service and select Go to Service(s). This takes you to the Services tab of the Task Manager, and the services that are running within that particular instance of svchost.exe are now highlighted. Again, under ordinary circumstances, there should be no need to disable any of these, as they are loaded and unloaded automatically by Windows. If you have trouble finding svchost.exe in the Processes or Details tab, click the Name or Image Name column at the top to sort alphabetically.

Windows Task Manager

Unlike other processes, the items running within svchost.exe are not executable files; they are dynamic link libraries, or DLLs. A DLL is a file containing information and functions that can be used by multiple apps at once. When a particular application needs info or functions that Windows itself ordinarily handles, it talks to svchost.exe, which knows what each DLL contains and can do. Since these are DLLs and not EXEs, the app making that request doesn't monopolize the data or functions. In other words, Windows can give different apps access to the same resource at the same time.

Disabling a service

If you are sure that you need to stop or disable a service, you can do that through the Services panel. Keep in mind that this course of action may break a core component, such as Internet access or the ability to log in to Windows itself. Because you're accessing core operating system functions, we recommend experimenting with one or two at a time rather than disabling a bunch of them at once. This way, if you experience a problem after disabling or stopping a service, you can figure out the culprit quickly, and you're less likely to trigger a cascade of problems. As the saying goes, with power comes responsibility. To access the Services panel, press Windows-R, type services.msc, and press the Enter key. Items in this window will be listed in alphabetical order by default. In Windows 10, you can also access this tool by clicking the Services tab in the Task Manager and clicking the link at the bottom labeled Open Services.

To stop a service, right-click it and select Stop. To disable it, right-click it, select Properties, press the Stop button, open the Startup Type drop-down menu, select Disabled, click the Apply button, and click OK to close the window. Ordinarily, you must stop a service before you can disable it. And the service may not be truly disabled until you reboot Windows.

Windows Services tool

Do not use the System Configuration tool (aka MSconfig) to manage services. This method can create serious problems. However, System Configuration's Startup tab can help identify third-party programs that may be slowing down startup. Beginning with Windows 8, the Startup tab in the Task Manager performs the same function as the tab in the System Configuration tool, plus it analyzes each program and tells you how much performance impact it has. As with your services, though, disabling these may break important things, so double-check to make sure that you're choosing the correct ones, and don't disable too many at once. To access MSconfig, press Windows-R, type msconfig, and press the Enter key.

The System Idle process

This one is a little confusing because of how it's labeled. The System Idle process just describes how much of your CPU is not being used. Its small RAM consumption is used to implement your CPU's power-saving technology, which varies from one chip to another. One common method is to repeat an instruction to the CPU to tell it to shut down elements of itself that are not being used. More recent CPUs have more sophisticated methods to save power, but newer chips also consume less power to begin with.

The print and fax spooler

Spoolsv.exe is the spool service process, which Windows uses to manage the data going to and from your printer or fax machine. Spooling allows Windows to manage print and fax jobs in the background. Sometimes you'll have a problem getting your printer or fax machine to work, and it's because spoolsv.exe got hung up somewhere. You may need to restart this process to complete your print or fax job. To do that, open the Task Manager, click the Services tab, scroll down to Spooler, right-click it, and select Stop Service. It will take a few seconds for the command to go through. Then right-click Spooler and select Start Service. In tougher cases, you may need to reboot your computer to restore printing and faxing.

Identifying other processes

In most cases, right-clicking a process in the Processes tab of the Task Manager and selecting Go to Service(s) will give you information about the app that's using that service, if it's not clearly stated in the Processes tab. In other cases, using this command will take you to the Services tab, but none of the services will be highlighted. In that case, the process isn't using a service, and you may need to look it up in a search engine to get more information about what it's doing. The System Idle process does not have a right-click menu at all, because its behavior is deeply embedded into Windows and is not subject to user interaction.

What *32 means in the Task Manager

If you're running a 64-bit version of Windows, you may see this tag at the end of the name of many processes in the Task Manager. It means that the service runs in 32-bit mode. This has no negative impact on performance -- modern 64-bit computers can run 32-bit software just fine, and sometimes software doesn't need to be optimized for a 64-bit platform anyway. The advantage of the higher bit range is mainly how much RAM the process can consume at once. A 32-bit app is limited to less than 4GB. Google Chrome might need more than that, but it runs its tabs in separate processes to increase security, and it's very unlikely that a single tab would need more RAM than that.

Do you have any tips or tricks for handling system RAM in Windows? Let us know in the comments below, or email us.

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Tom is the senior editor covering Windows at