I might not be a know-it-all software engineer paid handsomely in Silicon Valley, but I’m regularly amazed by how frequently friends and family reach out to me for tech support. While I secretly wish it wasn’t as frequent, in the past decade I’ve seen Windows spit up a BSOD or PCs just crash for all sorts of reasons-a botched software update, a driver conflict after installing a new piece of hardware, or just the cumulative effect of unintended misuse. A healthy chunk of these also complain of their computers “slowing down” or “acting weird.”
Before con artists sweep in to suggest they download more RAM from a fishy link, I prefer offering assistance with diagnosis and remediation. However, the real challenge is in going into the situation blind. I have little to no context for what set off the chain of problematic events and the user’s explanation is seldom helpful. That’s why I stopped showing up empty-handed. I now carry a keychain USB stick loaded with a curated arsenal of portable, free software. It’s my digital first-aid kit, equipped with everything I need to diagnose the problem, clean up the mess, and get the PC back up and running without wasting hours trying to download tools on slow or defunct machines.
TreeSize
Trimming the low-hanging fruit
Starting off slow with the frequent complaint of computers slowing down inexplicably, I love falling back on TreeSize Free. The software has a paid version too, but the free version with elevated administrator-level privileges works fine in a pinch. My usual suspect is an overloaded boot drive with no breathing room left for virtual memory, temporary files, and system updates. When storage runs out, performance suffers. Most novice users have no idea what’s hogging their storage in the background, and manually checking folder properties or sorting content by descending size is an exercise in futility.
With administrator privileges, TreeSize quickly scans entire drives and offers a clear, hierarchical view of your file system, sorted by size. More often than not, this approach reveals a forgotten multi-gigabyte game installation, a massive Downloads folder, or caches of video-editing software. This critical information accelerates the cleanup process, making it a surgical effort instead of a guessing game. It’s usually the first tool I run to solve the “slowness” problem in minutes, making me look like a wizard for simply pointing out a 100 GB folder of old phone backups.
R-Photo
The savior of corrupted data
Data corruption from incorrect flash drive removal is an everyday problem, and most of my avid photographer friends call me about unreadable SD cards after they yank it out of their computers without warning. Fewer still bother calling before sighing deeply and hitting Format, but for those who do, I have R-Photo. The interface is straightforward enough for a panicked user to understand. You select the corrupted drive (the SD card), and R-Photo performs a deep scan, bypassing the corrupted file system to look for recoverable file signatures.
It’s not always 100% successful, especially if the card is physically damaged, but in most cases of logical corruption, it does a remarkable job of pulling precious photos back from the brink. Moreover, it’s designed specifically to recover digital images and video files and supports a vast range of file formats, including the RAW files from most major camera brands.
Anything can render flash memory unreadable—improper ejection, power loss mid-operation, and even plain old card failure. It’s a good thing most memory cards and drives intended for professional use come with data recovery services offered complimentary for a fixed period, but R-Photo is a surprisingly powerful and completely free photo recovery tool that has saved the day for me on multiple occasions.
LatencyMon
Wired audio shouldn’t sound like Bluetooth
While I am on the subject of niche tools, it would be remiss to gloss over LatencyMon. This is ancient software, but it is still one of the most effective ways at measuring audio processing latency on any computer. Audio dropouts, stutters, and pops are often symptoms of high DPC (Deferred Procedure Call) latency, which is a fancy way of saying some other driver on the system is hogging the CPU and preventing immediate audio data processing so it feels real-time.
Importantly, this isn’t the latency induced by Bluetooth audio transmission from your computer to audio gear, but the kernel-level processing bottlenecks on your computer itself. Trying to find the process-hungry driver by guesswork is a nightmare you could spend hours on, and still come up empty. LatencyMon is indispensable, especially on older computers, because I just let it run for a few minutes while the audio issue is occurring, and it generates a detailed report. It will highlight the specific driver file (like ndis.sys for network drivers or nvlddmkm.sys for NVIDIA graphics) that is causing the highest execution times. With this data, my troubleshooting effort suddenly acquires a target.
EaseUS Partition Master
For when Diskpart.exe won’t play nice
Troubleshooting also comes bundled with the experience of building a new computer, and building half a dozen each year for friends and family quickly revealed that Windows’ built-in Disk Management tool often isn’t up to the task. I’ve struggled to get new disks to show up in Diskpart, let alone initialize them for active use. Odd issues also crop up when I need to resize the main Windows partition to create space for a new OS, clone an old, slow hard drive to a speedy new SSD, or fix a partition rendered unreadable. Microsoft’s command-line tool is powerful, but unforgiving and intimidating for novices or nervous troubleshooters.
For these situations, I rely on EaseUS Partition Master Free. It provides a clean, graphical interface that makes complex disk management tasks safe and intuitive. You can visually resize partitions with sliders, merge them without data loss, and convert disks from MBR to GPT with a few clicks (and a lot of patience). I’ve also used the disk cloning feature on occasion to upgrade existing builds with SSDs, since the tools make short work of migrating Windows to the new drive.
As opposed to Diskpart, EaseUS’ GUI also makes it a fine candidate for remote diagnosis, because I can easily guide family through the process virtually. When DiskPart.exe is throwing cryptic errors or the user is terrified of the command line, EaseUS Partition Master is the perfect tool to get the job done quickly and safely.
Revo Uninstaller
Undo that registry damage
All sorts of filth and nefarious software proliferate on the internet, and while the tech-savvy can curate reliable download sources, a vast majority of people are still none the wiser. When a friend says they “uninstalled” a program but are still having problems, it’s usually because the standard Windows uninstaller did a sloppy job. Many programs leave behind a trail of junk ranging from empty folders, user configuration files, and hundreds of useless registry entries. This digital detritus can cause software conflicts, error messages, and general system instability.
If I’m contacted to help with programs that refuse to uninstall too, I just point everyone to Revo Uninstaller. It works by first running the program’s built-in uninstaller and then performing its own deep scan for leftover files. The tool also scours the Windows Registry for any traces the original uninstaller missed and presents you with its findings. Revo offers options to clean all of this up with a single click. I also use Hunter Mode for persistent malware that shows up in Task Manager, but not in the list of installed programs.
BlueScreenView
Decoding the Windows BSOD
System crashes can easily throw even experienced troubleshooters into a panicked state. On Windows, they usually end up stuck on what’s come to be known as the Blue Screen of Death (BSOD). These are often unhelpfully cryptic, and you have just a few seconds to look up the error code before an automatic reboot attempt. It doesn’t need to be this way because BlueScreenView helps make sense of machine-specific codes without drowning you in advice that mostly points to an OS re-install as the fix-all solution.
NirSoft’s BlueScreenView on my USB stick is a brilliant little utility that analyzes the minidump log files that Windows automatically creates every time it crashes. When initialized, it shows a time-stamped list of all recent crashes in a simple, easy-to-read table. Each entry has the associated error name and the driver or system module that was likely responsible for the crash. If you see a repeat offender here, you can safely rule out a botched OS update attempt. This little tool converts the ambiguous BSOD into an actionable trail that leads right to the source of my woes.
Hiren’s BootCD PE
One recovery tool that does it all
This is the final trick I pull out of my bag, usually on computers that never woke up after one BSOD crash. A corrupted bootloader, a failing hard drive, or a ransomware infection can leave you with a completely unbootable machine. In these cases, all the other tools on my list are rendered useless because they need an OS. While Hiren’s BootCD PE is a godsend in such situations, you need to dedicate one thumb drive to it, and that’s my only qualm about it.
Once set up, it becomes a lightweight bootable instance of Windows 10. This transforms my flash drive into a boot drive, and I just need to set the BIOS to prefer booting from USB instead of the broken PC’s internal drives. When you boot a computer from it, you’re loading a clean, independent environment packed with a massive suite of free and open-source diagnostic and repair utilities. It includes tools for disk partitioning, data recovery, malware scanning, password resetting, and hardware testing.
Hiren’s is the ultimate safety net. From its self-contained environment, you can access the files on the computer’s internal drive to back them up, run a virus scan when the main OS is too infected to do so itself, or use command-line tools to repair a corrupted MBR. It gives you the power to troubleshoot and fix a system from the outside. You can also use tools like Rufus and Ventoy for creating a bootable USB.
I’d love to recommend a reliable free tool that automates driver updates on any PC, but the XDA team’s collective experience reveals these tools are unreliable at best and dangerous at worst. They often install incorrect or unstable drivers, causing more problems than we hoped they would fix. We recommend identifying hardware and manually identifying the correct driver files offered directly on the official manufacturer’s website.
A couple of USB drives could save you
Ultimately, having a dedicated bootable USB stick with a curated set of tools is about being prepared. No matter what you encounter on a friend’s broken PC or your own, this set of tools should prepare you for basic troubleshooting. At the very least, using a bootable USB will also equip you to diagnose the issue and make the affected PC functional enough to troubleshoot on-site, without bringing one of your own laptops just to download the required tools. Together, these tools are my powerful arsenal, and I rarely ever require anything else to get out of a sticky digital situation.