After my old Intel Pentium 4 3.2GHz two core processor powered Windows 7 SP1 64-bit system received its Meltdown/Spectre update, it slowed from a useable brisk walking pace to a crawl, especially when web browsing. Replacing Avast free 17.9.2322 with Panda Dome free 18.0.4 immediately restored it to almost the same speed as before.
What I am saying is that Avast needs to issue a stripped down no-frills Lite version. With Panda startup is quick and the system is at readiness for use much more quickly. I am sorry not to have the services of the excellent protection of Avast but I had no choice. Not all of us have the funds for new hardware. Having said that, there are now obvious security virtues in using such ancient processors as the AMD Athlon XP 3000+ or, better still, a Duron of the late 1990s.