Ubuntu and many other Linux distributions use the GRUB2 boot loader. If GRUB2 breaks—for example, if you install Windows after installing Ubuntu, or overwrite your MBR—you won’t be able to boot into Ubuntu.

Virtual machines are demanding beasts, providing virtual hardware and running multiple operating systems on your computer at once. As a result, they can sometimes be a little slow. Here are some tips to help you squeeze every last drop of performance out of your virtual machine, whether you’re using VirtualBox, VMware, Parallels, or something else.

The bash shell is the standard terminal environment included with most Linux distributions, included with macOS, and available for installation on Windows 10. It remembers the commands you type and stores them in a history file. You probably know a few basics of the bash history, but it’s a lot more powerful than you might realize.

Bash is the default command-line shell on most Linux distributions, from Ubuntu and Debian to Red Hat and Fedora. Bash is also the default shell included with macOS, and you can install a Linux-based bash environment on Windows 10.

Most Linux distributions include the bash shell by default, but you could also switch to another shell environment. Zsh is a particularly popular alternative, and there are other shells, like ash, dash, fish, and tcsh. But what’s the difference, and why are there so many?

When formatting partitions on a Linux PC, you’ll see a wide variety of file system options. These options don’t need to be overwhelming. If you’re not sure which Linux file system to use, there’s a simple answer.

Android isn’t largely thought of as a desktop operating system, but if you’re curious about how Google’s mobile OS works, running it on a device you already have isn’t a bad idea. This will give you an idea of what to expect on a phone or tablet, all without making a single change to your laptop or desktop since you can easily do this from a flash drive or memory card.

If there’s an Android application you really love and wish you could run on your computer, now you can: there’s a dead simple way to run Android apps on your PC or Mac without the fuss of moonlighting as an Android developer.

Windows 10, 8, 7, and Vista all support symbolic links—also known as symlinks—that point to a file or folder on your system. You can create them using the Command Prompt or a third-party tool called Link Shell Extension.

If you want to download an app not available in your country, connect to a company network on the road, or just stay safe on public Wi-Fi, you’ll need a VPN. Here’s how to connect to a VPN on your Android phone.

At this point, smartphones are prolific. We use them for calls, text messages, social networking, photos, quick searches, streaming music, watching videos…the list goes on. But each thing you do drains your battery life, and some apps will even continue to drain your battery in the background when you aren’t using them. A free app called Greenify can fix that.

A Linux live USB drive is normally a blank slate each time you boot it. You can boot it up, install programs, save files, and change settings. But, as soon as you reboot, all your changes are wiped away and you’re back to a fresh system. This can be useful, but if you want a system that picks up where you left off, you can create a live USB with persistent storage.

A bootable USB drive is the best way to install or try Linux. But most Linux distributions—like Ubuntu—only offer an ISO disc image file for download. You’ll need a third-party tool to turn that ISO file into a bootable USB drive.

If you’re an Android user, Google is ubiquitous throughout the operating system. You can access Google Now on Tap from pretty much anywhere by long-pressing the home button, jump into Google Now directly from the launcher, or say “OK Google” to use your voice from pretty much anywhere in the OS. But each time you do one of those things, it creates a new search entry in your Google History.

Modern PCs ship with a feature called “Secure Boot” enabled. This is a platform feature in UEFI, which replaces the traditional PC BIOS. If a PC manufacturer wants to place a “Windows 10” or “Windows 8” logo sticker to their PC, Microsoft requires they enable Secure Boot and follow some guidelines.

Android is very customizable–many of its features are just defaults, and can be swapped out for third-party alternatives without any rooting required. When it comes to iOS, well…not so much.

Android phones and tablets can fill up quickly as you download apps, add media files like music and movies, and cache data for use offline. Many lower-end devices may only include a few gigabytes of storage, making this even more of a problem.

Android’s notification system is easily one of its most powerful features. But with great power comes great responsibility, and some apps choose to abuse this. If you’re sick of constant notifications from specific apps, here’s how to completely disable them.

In order to set up an Android device, you have to sign in with a Google account. But you can also add more than one Google account, like a work or second personal account.

When you have multiple applications that do the same thing—like browsers, for example—Android will ask you which one you want to use every time, at least until you set one as the default with the “always” action. In the earlier days of the app picker, you’d have to clear defaults for each one before applying another, but things have changed.

Back in Android 4.2, Google hid Developer Options. Since most “normal” users don’t need to access the feature, it leads to less confusion to keep it out of sight. If you need to enable a developer setting, like USB Debugging, you can access the Developer Options menu with a quick trip into the About Phone section of the Settings menu.

If you have an Android phone or tablet with a small amount of storage, you probably keep uninstalling apps to make room for other ones. But there is a way to expand the storage of an Android device if it has an SD card slot.

Manufacturers and carriers often load Android phones with their own apps. If you don’t use them, they just clutter your system, or–even worse–drain your battery in the background. Take control of your device and stop the bloatware.

Ever want to watch a video on your phone or tablet without wasting its storage space? Or maybe you just need to view a file your friend gave you. Most modern Android devices support standard USB drives, so you can plug in a flash drive just like you would on a computer.

If you really want to dig into the Android system, you may find that some apps require root access. Rooting has become less necessary over the years, but it’s still useful if you want to run certain types of apps. Here’s the most widely supported method for rooting your device, and why you might want to.