The Short Answer
For a machine used daily: once a year is a sensible baseline.
For a machine that’s 3+ years old and used heavily: every six months.
For a machine used for work where downtime is costly: annually at minimum, with a check whenever you notice performance changes.
For a machine used lightly (occasional browsing, light documents): every 18–24 months is reasonable if nothing unusual is happening.
These are starting points. Below is a more detailed framework for making the decision.
Why Computer Age Changes the Calculation
Most computer components have predictable failure profiles. They’re least likely to fail in the first 18 months of use (early failures from manufacturing defects, typically covered under warranty). They then have a relatively stable period. After three years, failure rates begin to rise — particularly for:
Hard drives (mechanical): Average lifespan of 3–5 years under regular use. Drives that reach four years of daily use are statistically more likely to fail soon. SMART data often shows developing issues before complete failure.
SSDs: More reliable than HDDs for daily use, but they have finite write endurance. Consumer SSDs are typically rated for 300–600 TBW (terabytes written). High-use machines writing large amounts of data can approach these limits after several years.
Batteries (laptops): Rated for approximately 500–1,000 full charge cycles. At one full cycle per day, that’s 1.5–3 years before significant capacity loss begins.
Cooling systems: Dust accumulation in vents and fan bearings is cumulative. After two to three years, most laptops have enough dust to affect thermal performance. After four to five years, fan bearing wear becomes a factor.
An annual PC health check on an older machine catches these issues while the components are still functioning — not after they’ve failed.
Triggers That Warrant an Unscheduled Check
In addition to routine checks, certain events are worth treating as prompts for an immediate assessment:
The machine has become noticeably slower. Not the gradual kind of slowness that accumulates invisibly over years — but a step-change where you notice the machine is significantly worse than it was three months ago. Storage problems and failing drives commonly present this way.
You’ve had a malware infection. Even after removal, malware can leave behind components, modify system settings, or have exfiltrated credentials that require a clean-up audit. A check after an infection confirms the machine is actually clean and hasn’t had its security configuration changed.
You’re buying or selling a secondhand machine. A professional assessment gives an independent view of the machine’s actual condition — battery health, storage health, and whether anything is developing that wasn’t disclosed or wasn’t noticed.
Before a critical deadline or project. If you’re about to enter a period of intensive use where a computer failure would be seriously disruptive — a house move, a tax return period, a large work project — a health check beforehand is cheap insurance.
After any liquid exposure. Even a minor spill that the machine appeared to survive can leave residue that causes progressive corrosion. A check shortly after any liquid exposure is worth doing.
The fan has become noticeably louder. A laptop fan running at full speed constantly indicates the cooling system is being overwhelmed — either from dust accumulation, a failing fan, or a thermal paste that needs replacing.
Work vs Personal Use: Different Risk Profiles
Personal use: The consequence of a failure is inconvenience and potential data loss. If you have good backups, the stakes are lower. An annual check is appropriate.
Work use: The consequence of a failure includes lost time, missed deadlines, and potential data loss that affects more than just you. More frequent checks are justified, and the cost of a health check is trivial compared to a day of downtime.
Small business or freelance work: Your computer is effectively a piece of business equipment. Budget for an annual check the same way you’d budget for any other business maintenance. A failure during a busy period has a direct financial cost.
What Changes After Three Years
We see a clear shift in what health checks find on machines over three years old:
- Drive health warnings become much more common
- Battery capacity has often dropped to 70–75% of original on laptops that are charged daily
- Thermal throttling from dust accumulation is frequently present but unnoticed by the user — the machine is slower than it should be but the user has adapted
- Software security drift: outdated drivers, lapsed antivirus subscriptions, pending Windows updates that never completed
None of these necessarily means a machine is about to fail. But each one is better addressed proactively than after the fact.
A Practical Approach
- New machine (0–2 years): No routine check needed unless you notice problems. Keep backups current.
- 2–3 years: Consider a check if you haven’t had one. Good time to establish what condition the drive is in.
- 3–5 years: Annual checks are worth scheduling. The drive is the main concern.
- 5+ years: Annual checks are strongly recommended. At this age, storage, battery, and cooling all warrant monitoring.
Book a PC health check at our Putney workshop. We cover PCs, Macs, laptops, and desktops. Call 020 7610 0500 or contact us to book.