Having an anti-virus is no longer unusual for any computer user. There are a ton of anti-virus programs to choose from however. Many of these programs have huge space requirements and use a ton of memory that are large enough to make your computer slow.
Don’t worry, there is still something you can do. You can choose to use a light but powerful anti-virus program. When I say light, this means that the storage requirement and memory usage of the program will not be a reason for your PC to slow down, and it is still capable of doing its function which is to save your computer from any malware that might affect it.