I know it sounds like a no-brainer, but before you do anything else, restart your computer.  Matthew Petrie of Falcon Northwest technical support says that most of his customers solve their problems with this simple step.  “This long-standing maxim can work wonders,” says Petrie.

While you’re at it, make sure that your operating system is fully updated by running Windows Update. Neglecting updates could deprive you of important bug and performance fixes.

If you’re having problems with a peripheral, try switching it on and off. If that doesn’t work, try disconnecting and reconnecting the device. As a last resort, download the latest drivers and perform a full reinstall.

The first step to fixing a slow computer is to verify that your machine is the actual source of the problem. Videos that seem to buffer forever, and websites that take ages to load, may not be your computer’s fault. Geek Squad agent Derek Meister claims that many people mistakenly identify a slow system as the problem when “it’s actually not the computer, [but] their broadband connection.” See “Downloads are taking forever” below for instructions on how to use Speedtest.net to diagnose a slow connection.

If the problem is your PC, check whether you have plenty of free space on the hard drive holding your operating system. Windows needs room to create files while your system is running. If your hard drive is maxed out, performance suffers. Now is the perfect time to clear some space.

Microsoft’s System Configuration tool is your next-best bet for tackling slow performance. Many applications launch automatically when your machine boots up, which can stretch out boot time—especially on older, slower PCs. Make a habit of trimming the startup items. Open the tool by pressing Windows-R, typing msconfig, and pressing the Enter key.

Checking the Startup Item and Manufacturer columns is the best way to figure out which potential performance-killers you can safely disable. Avoid messing with any of the services and programs that have Microsoft Corporation listed as the manufacturer. Items such as AdobeAAMUpdater, Google Update, Pando Media Booster, Spotify, and Steam Client Bootstrapper are all fair game. Regardless, err on the side of caution: If you’re not sure what the program or service does, don’t disable it.

Speedtest.net is your best friend when you're having connectivity problems. Run a speed test to see what your download and upload speeds are—ideally they should be at least 50 percent of your Internet service provider’s advertised speeds, with a ping under 100 milliseconds.

If the speeds seem solid, make sure that you aren’t inadvertently downloading or uploading anything. Many torrent downloading programs run in the background and minimize into the system tray instead of the taskbar.

Check your network hardware. Updates for network cards aren’t all that common, but if your card’s manufacturer offers a newer driver, download it. Resetting your router and modem can help with connection problems, too. Most routers and modems have reset buttons, but pulling the power cable for a second or two can do the same thing. Don’t cut the power for much longer, or the hardware may reset itself to factory defaults.

Still having problems? Call your ISP, which can tell you whether the problem is on your end. As a last-ditch measure, the ISP could reset the master connection to your home.