From Ranger to IT

 The Day Every File Became an MP3 About five years ago, a ransomware attack brought a small company's entire computer network to a standstill. I was the company's outside IT person. They paid me a fixed monthly fee to manage their computers, network, and backups. I had been looking after their system for years. It started with a phone call on a Friday morning. "Something's wrong with our files. They've all turned into music files." Music files? I knew immediately this wasn't going to be a normal Friday. I told the employee not to touch anything and drove straight to the office. When I arrived, the problem was already spreading. One employee had opened an email attachment that looked harmless. Within minutes, JPGs, GIFs, DOCX files, and almost everything else had been encrypted. The files had strange new extensions, and none of them would open. The company's computers were all connected to the same network. That was the problem. The ransomware moved fro...

If you work with lookup tables in Excel, XLOOKUP is one of the most useful formulas you can learn. It was introduced by Microsoft in 2019 as the modern replacement for VLOOKUP and HLOOKUP—so if you haven't come across it yet, that's completely understandable, especially if you learned Excel before then. If you haven't read my earlier post on HLOOKUP and VLOOKUP , I'd recommend starting there and coming back to this one afterward—this post builds on that foundation. HLOOKUP vs. VLOOKUP vs. XLOOKUP HLOOKUP—use this when your reference table is laid out horizontally VLOOKUP—use this when your reference table is laid out vertically XLOOKUP—works in either direction and fixes several long-standing annoyances with the older two formulas Why is XLOOKUP better, not just newer? It can look to the left of the lookup column, which VLOOKUP can't do. It doesn't break if you insert or delete a column in the middle of your data You can specify a custom "not found" va...

  If you've worked in a spreadsheet where formulas broke the moment someone added a row, or where a chart stopped updating because it didn't "know" about the new data, you've felt the pain that Excel's Structured Tables were built to solve. Despite being available for well over a decade, this feature remains one of Excel's most underused and underestimated tools. Once you understand it, it's hard to imagine creating a business spreadsheet without it. What is a Structured Table? A Structured Table is what you get when you select a range of data and press CTRL + T(Windows) or CMD + T(Apple) . On the surface, it looks like a simple formatting upgrade: banded rows, a bold header, and a dropdown filter arrow on each column head. But underneath that visual polish is a totally different way of treating your data. Instead of thinking of your data as a static grid of cells(A1:H13), Excel now treats it as a named, self-aware object with defined boundaries, colu...

Not $600. Not $6,000. Sixty dollars—That was my entire income for the month, back in  2000, when even then, it was a painfully small amount. This is the story of how I got from there to becoming a college instructor in Canada—and why, even in the age of AI, I still think it was worth every sleepless night. No One Would Hire Me After immigrating to Canada in 1999, I wanted to continue the IT career I had built in Korea. So, I sent countless emails to companies across Canada, hoping someone would give me a chance. Not a single company offered me a job. Looking back now, I realized how unrealistic my expectations were. My English was still far from fluent, and I had absolutely no Canadian work experience. I was essentially asking someone to take a chance on a person who had nothing to prove himself with. Going Back to School at 37 So, I decided to start over from scratch. I figured that if two things could objectively prove my abilities in Canadian society, they were education and cer...

The hardest part of a job interview usually isn't knowing what to say. It's saying it while you're nervous. You can have the perfect answer sitting in your head and still ramble, freeze, or sound like you're reading from a script the second someone actually asks the question. That's why interview practice was never really about memorizing perfect answers. The point is to make the interview feel familiar enough that you can stop performing and start responding. There's a tool doing that now that almost nobody uses this way: you can rehearse a job interview out loud with AI. Several major AI assistants support conversations. Give one a real job posting, assign it a role, and you can run the interview as a back-and-forth conversation instead of a list of questions on a screen. Give AI the job. Then give it a personality. Start with a job posting for a role you actually want, and paste the full description into an AI assistant that supports voice. Then give it a rol...

My first job, back in the early 1990s, was as an Apple technician. On my first day, someone handed me a Macintosh—an IIci, I think, with a Motorola 68030—and basically left me alone with it. No manual, no training, no instructions. I spent three days poking around and figuring things out on my own. *Macintosh IIci from Wikipedia* That was the whole point of the Macintosh: a computer intuitive enough that anyone could use it without a manual. And it worked. I was proof of it. That experience shaped everything that came after. Palm Pilot, then BlackBerry, then the first iPhone in 2007. I never looked back. My whole family went the same way. iPhone, iPads, MacBook Pros—they've been our devices of choice for more than twenty years. Where the Cracks Started. But now, in 2026, I'm seriously considering a Samsung phone for the first time. I know switching won't be painless. Moving twenty years of data to a different ecosystem is a pain no matter how you do it. Still, this is the f...

  In the late 1990s, I worked as a general manager in the supply chain management department at a peripheral device distributor in Korea. Back then, no one in our department had any idea about the PMT formula, which calculates a fixed monthly loan payment. That formula was first introduced in 1985 in Excel 1.0 for Macintosh computers, so it already existed—we simply didn't know about it. Looking back, knowing the PMT formula would have let us walk into the bank with an exact number instead of guessing our way through every repayment plan. What I never learned back then, I now teach my college students. A Formula Even the Pros Often Miss I'm not the only one who found this formula unfamiliar. Several of my students who already work as accountants told me they'd never encountered PMT before, and they were genuinely grateful to learn it—proof that even seasoned practitioners often miss it. According to Statistics Canada, where I currently live, about 35.5% of Canadian homeowne...

There is a strange phrase in my web development class. "Hold tight, my love." I say it in every class. At first, students just assume it's some odd little pep talk of mine. "Hang in there, you've got this, you'll get used to it soon"—something like that, they figure. And when I finally reveal what it means, they crack up every time. I have to admit, it makes me a little proud. I'll tell you what it means in a bit. First, let me tell you where this phrase came from. Two Years of Wondering Why a Single Tag Was There Twenty-six years ago, I studied web development at BCIT (British Columbia Institute of Technology). It took a full two years. Looking back now, the question I struggled with most during those two years was actually pretty simple: "Why does this tag even go here?" When I first learned HTML, this is what I saw: a tag inside another tag, inside yet another tag. Some had to be closed once opened. Some had to be nested inside others. A...

  This is the list of hardware that we rarely see anymore, but modern products exist because of the groundwork they laid. That's why I named the title starting with Ubuntu*. Today's newer products have been produced because of these old, obsolete devices. 1. Storage Devices Floppy Disk: A magnetic medium that holds 720KB or 1.44 MB of data, used for storing data and operating systems. CD-ROM: A 650 MB optical compact disk used for storing data, music, and applications. DVD: A digital video disk with 4.7GB to 17.08GB of capacity, used mainly for storing videos. Blu-ray disk: An optical disk ranging from  25GB to 128GB, used for storing movies with multiple language tracks and subtitle options. Hard Disk Drive(HDD): A storage device that uses a spinning motor and magnetic platters to read and write data. 2. Dial-up Modem Connected to the internet over a phone line at speeds up to 56.6 Kbps. 3. Printer Laser printer: Toner(a black or coloured resin powder) is used. Inkjet printer...

VLOOKUP and HLOOKUP do the same basic job—but they look in completely different directions. Here's the easiest way to remember them: VLOOKUP goes vertical. HLOOKUP goes horizontal. That's it. Picture a potluck at work. You've got a sheet with everyone's name, their department, and what they're bringing. I laid out that same information two ways: a normal table running top to bottom on the left, and the same data flipped sideways on the right, with names running across the top instead. That's really the key difference between the two. VLOOKUP searches down a column; HLOOKUP searches across a row. Neither one is better. The direction of your table determines which one makes sense. VLOOKUP: The Vertical Table If I want to know what Kevin's bringing from the left-hand table, the formula is: =VLOOKUP(B9, A3:C6, 3, FALSE) B9 is the cell where I typed his name. A3:C6 is the table Excel searches—it scans down the first column looking for a match. 3 tells Excel to r...

Hello, and welcome.  A lot has changed in technology since I started working in IT, and I've changed along with it. Over the years, I've worked in different IT roles, from technician to business owner, tutor, and eventually college instructor. Through all these years, one thing has remained constant: learning. That's one of the reasons I've decided to start writing again. This blog will mainly focus on practical IT knowledge and real-world experience—computers, networking, troubleshooting, software, hardware, and other technology-related topics. I'll try to keep things clear, practical, and accessible. But it won't be only about technology. I'll also be sharing stories from my military days . In South Korea, military service is compulsory for most men—and I went in later than most. And as if going late wasn't enough, I ended up at a Ranger School known for exactly one thing: turning you into someone who crawls, rolls, sweats, and questions every life cho...