I'm Dave. I've been fixing Windows problems in Somerville, NJ since 2011. A repair install — also called an in-place upgrade — is one of the most powerful tools for fixing a Windows 10 installation that's gone wrong without wiping your files. This guide walks you through the whole process. And I'll be honest with you about the point where it's smarter to bring it in than to proceed on your own.
Before you start, understand what you're doing. A repair install and a factory reset are not the same thing, and confusing them is a costly mistake.
A Windows 10 repair install — officially called an in-place upgrade — runs the Windows 10 installer over your existing Windows installation. It replaces core system files with fresh, uncorrupted copies from the installer while leaving three things intact: your personal files, your installed applications, and your Windows settings. Think of it as replacing the engine in the car without touching the interior.
This makes it different from two alternatives people often confuse it with. A Windows Reset ("Remove everything") wipes your files and reinstalls Windows from scratch — that's a clean install, not a repair. A "Keep my files" Reset preserves personal files but removes your installed apps. A repair install preserves everything — files, apps, and settings — while replacing the broken system components underneath.
A repair install is a significant operation. If your hardware has problems going in, the process can fail midway and leave Windows in a worse state than before. Check both columns before proceeding.
A repair install is designed to preserve your files. That doesn't mean it always does. Back up first, every time, no exceptions.
In the vast majority of cases a repair install completes without issue and your files are exactly where you left them. But "vast majority" is not "always." If the process encounters a drive error midway through, hits a power interruption, or runs into an unexpected compatibility problem, it can fail in a state that leaves Windows partially written and your data inaccessible.
Five minutes of backing up the most critical files before you start is cheap insurance. At minimum, copy your Documents, Desktop, Pictures, and any other folders with files you can't afford to lose to an external drive or upload them to OneDrive or Google Drive. If you have specific software with local data files — QuickBooks, Outlook PST files, project files — those too.
This runs from inside Windows. You need an internet connection, about an hour of time, and at least 20GB of free space on your C drive.
Go to microsoft.com/en-us/software-download/windows10 and click Download tool now. This downloads the official Microsoft tool that will fetch the Windows 10 installer files. Do not download Windows 10 from third-party sites — only from Microsoft directly.
Run the downloaded tool (MediaCreationTool.exe) as administrator — right-click, Run as administrator. Accept the license terms. When it asks what you want to do, select "Upgrade this PC now". Do not choose "Create installation media" — that's for making a USB drive to install on a different machine.
The tool downloads the installer, verifies the download, and prepares the installation files. You'll see progress bars for each stage. This can take 20–60 minutes depending on connection speed and how fast your drive reads and writes. Don't interrupt it.
After preparation completes, the installer will ask what you want to keep. Select "Keep personal files and apps" — this is the repair install option that preserves your data and installed programs. Review the summary screen carefully before clicking Install. It should confirm: "Keep personal files and apps." If it shows anything else, stop and recheck the option.
Once you confirm and click Install, the repair install begins. The machine will restart multiple times as it applies system files, configures the installation, and brings Windows back up. You'll see progress percentages on a black screen. The whole process typically takes 30–60 minutes after clicking Install. Do not interrupt it.
When the machine boots back into Windows, you'll go through a brief setup sequence — signing into your Microsoft account, privacy settings, and a few configuration steps. Once on the desktop, verify that your personal files are still present in Documents, Desktop, and Pictures. Check that your main applications still launch. Run Windows Update to pick up any patches released since the installer was built.
A repair install is a solid DIY option when the machine is healthy. There are situations where proceeding without a diagnostic first is a real risk to your data.
I'll be direct about this: if there's any doubt about your drive's health, or if you're not 100% sure the problem is software rather than hardware, a $75 diagnostic before a repair install is a much cheaper outcome than data recovery after one goes wrong.
Here's the specific scenario we see at the counter regularly: someone's Windows has been acting up for a while, they find the repair install guide online, they run it on a machine whose drive is showing early failure signs they weren't aware of — and the installer hits a bad sector midway through the write process. The machine is now in a partially-written state, Windows won't boot, and recovery is more complicated than if they'd started from a known-good drive.
The diagnostic tells you: is the drive healthy enough to support this? Is there malware that a repair install won't clear? Is the real issue hardware rather than software? If the answer to any of those changes your plan, it's worth knowing before you run the installer, not after.
Bring it to our Somerville NJ shop first. Our $75 bench diagnostic checks drive health, RAM, and system integrity — and tells you whether a repair install is the right move or whether something else is going on under the hood. The $75 is credited toward any repair if you move forward with us.
📞 Call (908) 428-9558 — Book a DiagnosticWalk-in welcome · No appointment needed · Drop-off only · 75 N Bridge St, Somerville NJ
From Bridgewater to Princeton, customers across Somerset and Middlesex County trust Dave's with their Windows problems.
"My Windows 10 was crashing constantly after an update. I tried the repair install guide myself and something went wrong mid-process. Brought it to Dave's — they recovered my files, fixed the install, and told me my drive was showing early failure signs that caused the problem. Wish I'd come in first."
"Windows kept blue screening after a failed update. Brought it to Dave's, they ran a diagnostic first — drive was fine, it was just corrupt system files. They did the repair install properly, everything works perfectly now. No data lost."
"I wasn't sure if my issue needed a repair install or something else. Dave's diagnosed it in an hour, told me what was actually wrong, and fixed it the same day. The $75 diagnostic was the right call. Saved me from doing something that might have made it worse."
We run the $75 bench diagnostic before recommending a repair install, clean install, or any other approach. The diagnosis determines the plan — not the other way around.
If there's any risk to your files, we address that before proceeding. We won't run a repair install on a machine with a marginal drive without telling you clearly what the risk is.
A repair install doesn't always clear deep malware infections. We check for active infections before the repair so you're not putting a clean Windows on top of a system that's still compromised.
Most Windows repair jobs are done same or next business day. Drop it off in the morning, pick it up fixed — with your files intact and all drivers updated.
Your computer never ships anywhere. We work on it at 75 N Bridge St in Somerville. If something comes up after the repair, you know where to find us.
We've been fixing Windows problems in Somerville since 2011 — every version, every failure mode. If Windows is broken, we've probably seen it before.
A repair install (in-place upgrade) reinstalls Windows 10 system files over your existing installation using a fresh copy of Windows — replacing corrupted or missing components while keeping your personal files, installed applications, and settings. It's the middle ground between leaving a broken Windows alone and wiping the drive for a clean install.
It's designed not to — but it's not risk-free. If the drive has underlying hardware problems or the machine has an active malware infection, the process can fail midway and leave the system in a worse state. Always back up your files before starting, and check your drive health with CrystalDiskInfo first. If the drive shows anything other than "Good," bring it in for a diagnostic before proceeding.
A repair install (in-place upgrade using the Media Creation Tool) keeps your files, apps, and settings while replacing system files. A factory reset's "Keep my files" option keeps personal files but removes installed apps. A factory reset's "Remove everything" option wipes everything. For most Windows software problems, the repair install is the right first move because it preserves the most.
If the repair install failed midway, don't keep retrying without knowing why it failed. Bring it in. We'll check the drive health, determine what caused the failure, and either safely retry the repair install or recommend the right alternative based on what the machine's hardware actually supports. A failed repair install doesn't necessarily mean your data is gone — but further attempts without diagnosis can make recovery harder.
Try the repair install yourself if: the drive checks out healthy, the machine boots to Windows, you've backed up your files, and the problem is clearly software behavior. Bring it to Dave's first if: you're not sure about the drive health, the machine has had malware, it won't boot at all, or you're not comfortable with the process. The $75 diagnostic tells you exactly what's going on before you touch anything — and it's credited toward the repair if we do the work.
Yes. We handle Windows repair, clean installs, virus removal, and data recovery at our Somerville NJ shop. Drop-off only at 75 N Bridge St, no appointment needed. Call (908) 428-9558 with any questions before you come in.
First time visiting Dave's Computers? Take $20 off your labor on any repair at our Somerville NJ shop.
Show this coupon at drop-off. Mention code "WIN20" at the counter or when you call.
Code: WIN20 · Dave's Computers · 75 N Bridge St, Somerville NJ 08876 · (908) 428-9558
One location, drop-off only. Dave's Computers has one location at 75 N Bridge St, Somerville NJ 08876. We do not offer on-site or in-home service anywhere in New Jersey. All repairs are performed at our Somerville shop. Curbside drop-off is available.
Drop it off at our Somerville NJ shop. We'll run the diagnostic, tell you what's going on, and fix it right — without risking your files in the process.
📞 (908) 428-9558