Upgrade or replace? Deciding what to do with an ageing computer

Diagnose first

A “slow computer” can have various causes, and each has a different fix. In Windows, open Task Manager (Ctrl + Shift + Esc), go to the Performance tab, and watch it while doing whatever is slowing you down:

What you see	Likely cause	What helps
Disk at 100 %, long loading times	a hard disk (HDD) or an almost full drive	an SSD, freeing up space
Memory near the maximum	not enough RAM	more RAM, fewer programs running
Processor at 100 % on a single task	processor too weak for the job	a processor upgrade or a new computer
Games stutter, GPU at 100 %	graphics card too weak	a new graphics card (desktop)
High temperatures, loud fans, fluctuating performance	dust, old paste	cleaning and maintenance

On a Mac, Activity Monitor shows similar information.

Cheap upgrades with a big effect

An SSD instead of a hard disk. On a computer whose system is on an HDD, this is the most noticeable change. The system and programs start faster because an SSD has no mechanical heads. How to choose one is covered in the SSD and HDD guide.

More RAM. This only helps if memory is genuinely running out. You must use the same type (DDR4/DDR5, UDIMM/SO-DIMM) that the board supports.

The limits of the platform

For the processor, the socket and the board’s support decide. AMD’s AM4 platform, for example, supports processors from Ryzen 1000 to Ryzen 5000, but not every board supports every generation – AMD publishes a compatibility table by chipset. Moving to AM5 means a new board and DDR5 memory.

If you would be replacing the processor, board and memory all at once, the upgrade is close to building a new computer. In that case, compare what you would keep from the old build (case, power supply, drives, graphics card).

The operating system

Microsoft ended support for Windows 10 on 14 October 2025. The computer keeps working, but it no longer receives security fixes. For home users there is an Extended Security Updates (ESU) programme until 12 October 2027.

Among other things, Windows 11 requires a compatible 64-bit processor, 4 GB of RAM, 64 GB of storage, UEFI with Secure Boot and TPM 2.0. An older computer that does not meet them can still be useful, for example with another supported operating system – but that decision is beyond the scope of this guide.

The decision process

Use our Upgrade or replace? tool. Based on your answers about the type of computer, its drive, memory and OS support, it shows you which steps make sense and in what order.

If you decide to replace it

The old computer can still be useful – as a spare, for the children, as a home server. If not, hand it in as electrical waste (to the retailer, one for one, when buying a new one, or at a collection point), and securely wipe the drives first.