My Computer Is Slow: 7 Causes and Solutions by Our Longueuil Experts
“My computer is slow, I can’t take it anymore!” Without a doubt, this is the sentence we hear most often at the TechAuPoint counter at 4172 Grande Allée in Longueuil. Whether you open Chrome and it takes 30 seconds to load, Windows 11 takes 5 minutes to start, or your PC freezes as soon as you open 3 tabs: the frustration is real, and it costs a lot of wasted time.
The good news? In 90% of cases, a slow computer is not a computer to throw away. With proper diagnosis and the right intervention, you can often double or triple the performance of a 4-to-6-year-old PC. The key is identifying the real cause among the many possibilities.
In this guide, our A+ and CISCO certified technicians present the 7 most common causes of a slow computer, in the statistical order we diagnose them every week. And most importantly, what we concretely do to fix them.
Why is my PC slow? Statistics from our shop
Out of hundreds of computers we handle each year in Longueuil, here’s the real breakdown of slowdown causes:
- 35% → Mechanical hard drive (HDD) instead of an SSD
- 25% → Startup programs piling up
- 15% → Saturated or insufficient RAM
- 10% → Viruses, adware, or unwanted software
- 8% → Aging or failing SSD
- 5% → Overheating and dust
- 2% → Corrupted Windows requiring reinstallation
Let’s look at each cause in detail, with concrete solutions.
Cause #1: You still have a mechanical hard drive (HDD)
This is by far the most frequent cause. If your PC dates from before 2024 and you’ve never modified the storage, you probably still have a mechanical hard drive (HDD) spinning at 5400 or 7200 RPM. Compared to a modern SSD, that’s about 20 times slower for everyday operations.
The solution: SSD installation South Shore
The HDD → SSD replacement is the most cost-effective upgrade in computing. For $80 to $150 of parts, you literally transform a PC. Windows startup: from 2 minutes to 15 seconds. Chrome opening: instant. We offer SSD installation South Shore with complete cloning of your Windows system, with no data loss or software reinstallation. Check our hardware installation page for service details.
Cause #2: Too many startup programs
On a PC with 3-4 years of normal use, we often find 20 to 30 programs automatically launching at every startup: Adobe Creative Cloud, Dropbox, Google Drive, OneDrive, Spotify, Teams, Zoom, Steam, Discord, iCloud, two or three HP or Dell utilities, and sometimes (the worst) two conflicting antivirus programs.
How to check
Press
Ctrl+Shift+Esc
to open Task Manager, then click on the Startup tab. You’ll see the list with the impact of each program. Disable everything you don’t use daily.
It’s a simple step, but it requires knowing what to disable without breaking anything. It’s included in our express service if you’d rather have a technician do it in 15 minutes.
Cause #3: Not enough RAM (memory)
Many laptops sold in Quebec between 2017 and 2023 shipped with only 4 GB of RAM. At the time, it worked. In 2026, with Chrome consuming 500 MB per tab, Microsoft Teams running constantly, OneDrive in the background, and Windows 11 itself using 3 GB, it has become unworkable.
When RAM is saturated, Windows starts using the disk as memory (the “swap”), and everything slows down, even with an SSD.
The solution
If the RAM is expandable (accessible SO-DIMM slot), we upgrade to 8 or 16 GB. If it’s soldered to the motherboard (increasingly common on recent ultrabooks), the only option is to change machines. Our computer diagnostic Longueuil starting at $29 identifies in less than 24 hours whether your PC is upgradable.
Cause #4: Viruses, adware, and malicious software
Modern viruses no longer pop up red windows screaming “YOUR PC IS INFECTED.” They install quietly and consume your resources to mine cryptocurrency, send spam, or steal banking data. Symptoms: fan running full speed at idle, hot PC, browser redirected to weird pages, invasive ads.
The solution
Our virus removal service includes a complete scan with multiple professional tools (beyond Windows Defender), removal of all detected strains, registry cleanup, and browser reset. If the infection is too deep, a complete format at $89 may be more economical.
Cause #5: Your SSD is aging (yes, it happens!)
Many people think an SSD never ages. False. Entry-level SSDs installed in 2018-2020 PCs (Adata, Crucial BX500, WD Green) have limited endurance. Windows 11 writes a lot to disk: telemetry, logs, updates, Chrome and Edge caches. After 4-5 years of heavy use, these SSDs slow down because their controller spends more time managing worn blocks.
The solution
A free tool like CrystalDiskInfo lets you see the SMART status and wear percentage of your SSD. If you’re past 80% wear, replacement is mandatory. Today we install NVMe SSDs that offer 5 to 10 times better performance than an entry-level SATA SSD.
Cause #6: Overheating and accumulated dust
This is the underestimated cause. When a PC overheats, the processor automatically reduces its frequency to avoid burning out, that’s thermal throttling. Result: an i7 that should run at 4.5 GHz drops to 1.2 GHz, and everything slows down. The cause? Dust, everywhere, in the fans and processor heatsink. On a 3+ year-old PC that has never been opened, it’s guaranteed.
The solution
Our PC dust removal service includes complete cleaning with compressed air and fan verification. On an overheating PC, the performance gain after dust removal can reach 30 to 50%. To learn more, Tom’s Hardware regularly publishes excellent technical articles on thermal dissipation.
Cause #7: Corrupted Windows after years of use
After 3 to 5 years of installations, uninstalls, failed updates, and other accidents, Windows itself becomes slow. The registry is fragmented, dependencies are broken, and services run for nothing. No “magic cleaner” can fix this (most tools found on Google’s first page are at best useless, at worst harmful).
The solution
A clean format with Windows reinstallation from scratch. That’s our format and reinstallation service at $89, including backing up your data before the operation and reinstalling your essential software after. The PC comes out like new, guaranteed.
My computer is slow: where to start?
With 7 possible causes, the worst mistake is to guess. You risk spending $100 on RAM when it was a virus, or formatting Windows when you just needed to replace the SSD. That’s why we always recommend starting with a professional diagnostic.
Our computer diagnostic Longueuil service starting at $29 precisely identifies the cause of slowness in less than 24 hours. Memory tests, SMART disk verification, antivirus scan, temperature monitoring, startup program analysis: we cover everything. At the end, you receive a transparent quote with only what your PC actually needs.
Our goal is not to sell you unnecessary hardware. It’s quite the opposite: we are specialists in speed up PC Longueuil at the fairest price, often up to 50% less expensive than the competition. Our South Shore clients (Longueuil, Greenfield Park, Saint-Hubert, Saint-Lambert, Brossard, Boucherville) come back precisely for this: honesty, expertise, and results.
The golden rule of slow computer repair
Before throwing out your current PC and buying a new one at $1,500, ask yourself: have I really tried a hardware upgrade? On a 5-7 year-old PC, $100 to $200 of investment (SSD + installation) is often enough to bring it back to the level of a new PC for office work, web browsing, and even some games. Our slow computer repair service is designed exactly for that: extending the life of your hardware, not pushing you to buy more.
Is your PC dragging and wasting your time? Bring it to us at 4172 Grande Allée in Longueuil, or request our in-home service anywhere on the South Shore. Diagnostic starting at $29, honest quote, guaranteed results. Contact TechAuPoint right now.
FAQ: Your questions about slow computers
Why is my PC slow when it isn’t even old?
A recent PC that lags is often a victim of too many startup programs, a lack of RAM (the 4 GB from 2021 isn’t enough in 2026), or unwanted software installed without knowing. More rarely, it can be an entry-level SSD failing prematurely. A $29 diagnostic identifies the real cause in minutes.
How much does an SSD installation cost at TechAuPoint?
SSD installation at TechAuPoint Longueuil costs $49 in labor, plus the SSD price (generally between $80 and $150 depending on capacity and quality). We can also do a complete cloning of your current Windows system, with no software reinstallation needed. Most installations are completed same day.
My computer is slow: should I replace it or repair it?
It depends on its age and overall condition. For a PC less than 7 years old in good physical condition, an SSD + RAM + dust removal upgrade (often between $150 and $250 all included) gives spectacular results. Beyond 8 years, or if the motherboard and processor are really outdated, replacement becomes more economical.
How long does a slow computer repair take in Longueuil?
At TechAuPoint, 90% of our interventions are completed same day. A dust removal takes 1 hour, an SSD installation with cloning takes 12-24 hours, a virus cleanup takes 2-4 hours. If your PC is your main work tool, let us know: we prioritize urgent cases when possible.
Does cleaning the Windows registry really speed up my PC?
No. It’s one of the most widespread myths. Windows has managed its registry automatically since Windows 7. “Registry cleaner” software is at best useless, and several have actually broken systems that clients brought us for repair. If my computer is slow, the cause is elsewhere: hardware, startup, RAM, viruses, or disk wear.
