Computer freezing for 1-2 seconds every now and then, more often after prolonged use

I have had a problem with my computer for quite a while lately.

It freezes for 1-2 seconds no matter what I am doing at the moment The longer I use it, the more often it happens, starting from maybe once per hour down once every 5 min First I thought it was a memory leakage

But now I noticed that the CPU is spiking to 100% sometimes as the freeze happens Just as I am writing this it spiked again, but this time only up to 80% If I were able to catch it right, it seemed like it were explorer.exe that used the CPU?

Could this be a virus, how do I check that and fix it?