I'd recommend checking out local IT shops or freelance tech professionals. They can provide hands-on help with your computer health check, upgrading your virus software, and improving your WIFI.If you're comfortable with a bit of DIY, you might also consider upgrading some PC components yourself. Websites like Starla offer a wide range of PC components, including CPU, which can be relatively easy to install with a bit of research. Here you can find more details if you need it:
https://starla.uk/product-category/pc-c ... ssors-cpu/I've personally found that a combination of professional support and DIY upgrades can be a cost-effective way to keep your computer running smoothly.