Earlier this year, I tried running a full Windows installation from a flash drive, and it worked. That got me thinking, if I can run Windows from a flash drive, shouldn't it work with an SD card too? Microsoft had a "Windows To Go" feature that allowed this kind of setup, but it was discontinued in 2019. Since then, anyone who wants to run a portable Windows installation has to rely on a third-party tool like Rufus. That's something I already had.

Now it was time to pick an SD card. After some research and based on my experience, I knew an older-generation SD card was unlikely to work. Windows would perhaps load, but it would be frustratingly slow. That happened the last time when I used a USB 2.0 flash drive, where I was stuck on the "Getting devices ready" screen for hours. So, I got a SanDisk Extreme microSD UHS-I card. It boasted read and write speeds of 190 MB/s and 90 MB/s, respectively. It's certainly not as fast as an SSD, but it's pretty much in the same range as an HDD. And if a hard disk drive can run Windows, so should an SD card. At least that's what I thought initially.

The setup was fairly simple

You will need a fast SD card and some patience

Installing Windows on the SD card took me over two hours with Rufus, but the process was fairly simple. I inserted the SD card into the built-in card reader on my laptop, launched Rufus, selected the Windows 11 ISO, picked Windows To Go as the Image option, and hit Start. Two hours and sixteen minutes later, the SD card was ready. As I said, it's simple, but you will need some patience. I would also like to highlight that if you are using an external card reader, make sure it's fast enough and plugged into a USB 3.0 port if your laptop has one. Using the USB 2.0 port will result in slower performance.

The next step was to change the boot order so that the system boots Windows from the SD card rather than the built-in SSD. Once that was done, it took close to 15 minutes to get past the initial "Getting ready" screen. After that, I had to set up Windows the way it is in any regular installation, connect to a network, pick a region, wait for pending updates to install, and so on. For an SD card, this part was surprisingly fast, and it never felt like I was not dealing with a proper storage drive. That's when I got my hopes up with the setup.

It handled everyday tasks well

Portable Windows works much like a regular installation

I will be honest, I didn't test the setup for heavy workloads. An SD card isn't designed to handle these kinds of operations, so I limited testing to everyday tasks, things an average user does on a laptop. As soon as Windows booted, I first checked the Task Manager to verify that everything was in order. Since it was a new Windows installation and pretty toned down, thanks to Rufus, which let me disable Copilot, OneDrive, and other resource-intensive features, the resource consumption was in the normal range.

Now it was time to start testing. First, I installed ShareX from the Microsoft Store, and the entire process took less than 30 seconds, the same as a regular Windows installation on an HDD or SSD. So, installing apps wasn't a problem. Next, it was time to test whether the setup could be used for web browsing, and it worked flawlessly. Even with several active tabs, the system never showed signs of slowdown. I watched entire YouTube videos alongside active downloads, and the system was surprisingly stable. And the boot time wasn't too slow either. It took a few minutes on the first attempt, but subsequent reboots were under a minute.

Now, it was time to play games. Again, I wasn't going with any modern-day title. It was the built-in Solitaire. Ideally, it's one of the first apps I uninstall on a new Windows PC, but not this time. As I expected, the game ran perfectly. Lastly, it was time to verify whether Windows updates would install. When I checked, there were around 15-20 pending updates, and except for two, every update installed without an error, even the optional ones.

I used the setup over the weekend for the same set of tasks over and over again, including some small and large file transfers, and it was perfectly usable. The transfer speeds were not exceptional, but it was doable. I was getting between 250Kb/s and 2 MB/s. The only issue I noticed was a delay in loading previews when hovering over apps in the taskbar. Of course, if you try this on a relatively low-end SD card, performance may vary, but as long as the SD card can handle it, Windows will boot and run.

Performance and reliability weren't major concerns

There were initial issues, but none turned out to be deal-breakers

Since I had already run Windows from a flash drive, I had a hunch that an SD card would work. And as it turns out, it didn't just make the cut, but there were no major issues with performance or reliability. The system never crashed or threw any errors. But it wasn't a completely smooth ride either.

The system didn't recognize my external monitor, even though it was connected via cable. The problem, as surprising as it may sound, went away after an hour or two, so I never really got to troubleshooting whatever caused it. So, if you ever run this kind of setup, keep in mind that such problems may show up, though they are all easily fixable.

It's not replacing my regular Windows setup

But portable Windows is useful in many cases

The two days I spent running Windows from an SD card taught me that the idea behind a portable Windows installation isn't all that bad. Instead of taking your laptop around, you just keep an SD card or a flash drive, plug it into another system, and you have your own setup right there. It can even serve as an emergency system if your drive ever fails.

All that said, a Windows To Go installation can't replace my existing setup. Perhaps running Windows from an external SSD might work, but it's simply not as reliable as the built-in drive. There are too many variables at play. That's why I said, the idea is good, but it's not practical as a long-term setup.