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ZDNET's key takeaways

• Dozens of processes run in the background on your PC, and each takes a bit of memory.
• Most are necessary and helpful, but some can be disabled to optimize performance. 
• Checking to see which ones load automatically is a good place to start. 

PC feeling a little sluggish? There are myriad possible reasons, but one of the best places to start is checking what's tying up your memory. 

If you open the task manager (Ctrl + Shift + Esc) and sort the programs by memory usage, you'll find the usual culprits (your browser, Microsoft Office apps) at the top of the list, and a handful of others you probably can't identify.

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Unfortunately, many of these processes are necessary and/or inconsequential in terms of overall memory usage. But there are certainly some processes that can speed things up when killed -- especially if you're on a slower PC. 

I recommend identifying the biggest culprits of memory leakage first: excessive browser tabs, bloatware from your PC's manufacturer, and applications that start up on their own (whether you use them or not). There's also a process called SysMain that preloads apps on your PC you may want to disable. Let's walk through them. 

1. Your browser

I'm willing to bet the app at the top of the list is your browser. Google Chrome and Microsoft Edge are notorious memory hogs, especially when you have dozens of tabs open. One thing you may not be aware of: Chrome has its own task manager, so you can see exactly which tabs are costing your PC the most memory. 

In the three-dot menu in the top-right corner, go to More Tools > Task Manager. Sort by memory footprint, and you'll very quickly be able to see if there's a particular tab that's chewing through your RAM. Luckily, you can close them right here in the task manager. 

2. SysMain

If you do any Googling of this topic, you'll see some discussion of this one. SysMain (formerly known as Superfetch) is a Windows process that pre-loads programs it knows you use regularly. This results in tying up some memory, which could negatively impact performance on some PCs. 

There is a lot of discussion on both sides. Some Windows users swear that disabling this process improved their PC's performance, while others cite that it should have no real impact at all. If you're looking for solutions, however, it's worth a try. Here's how. 

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Press Win + R to open the Run command and type services.msc in the dialog box. This will display all background processes currently running on your PC, complete with descriptions to help identify what they do. 

Scroll down to SysMain, and double-click it. It's currently running by default, so first click the Stop button. Then, locate the dropdown menu next to Startup Type, and select Disabled. Then click Apply, and OK. Windows will no longer preload apps, potentially freeing up some memory in the process. 

3. Manage your startup apps

Nearly every app you install wants to launch automatically when you start your PC. While this makes sense for some, there's no point in devoting system resources to programs you're not using. 

We covered how to check what apps start automatically in Windows 10, and the process is the same with Windows 11. Press Ctrl+Shift+Esc to open the Task Manager, then go to the Startup tab (you may need to click "More Details" to see it). This list shows you all the apps your PC launches automatically when you start your computer. 

You'll probably see a few apps that don't need to be there, and you can disable these simply by right-clicking. Note that this doesn't uninstall the programs; it simply relegates them to launching on your command. 

Processes you disable should remain in this window, should you want to re-enable in the future. If you don't see it, however, you can re-enable it in a command prompt. From the start menu, type cmd, right-click on Command Prompt, and select Run as administrator. Type the following: sc config "SysMain" start=auto & sc start "SysMain" and then restart your computer.

4. Bloatware

The previous step may have identified a few bloatware programs you've never used, but nonetheless have been running on your PC since you bought it. Most laptops come with proprietary apps that are often half-baked or not particularly useful, as manufacturers try to boost brand recognition and inflate the value of their PCs. 

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Fortunately, they can usually be easily removed, freeing up valuable space and memory. After removing them from the automatic startup menu, you'll find them in Windows' Add or Remove Programs menu, where you can uninstall them.