Slow system's peformance

Currently running Windows 7 Ultimate 64bit(service pack 1) and while It is several years old, its being constantly updated, protected by up-to-date Malwarebytes Pro and AVG Anti-virus. However after all these years, for quite a while now its been running rather painfully slow. For example when booting, the screen with Windows logo alone loads for like 2 minutes plus the blue screen(loading) before actually desktop appears.
Even when system is fully loaded its spiking, running some programs smoothly, some - painfully slow.
The most important issue is that I am nable to boot in Safe mode, everything works until a point, specifically - pressing F8 ---> Selecting ''Safe Mode'' ----> Loads files and that's where it stops, it freezes with a list and ''please wait'' at the lower left corner, i leave it for over half an hour and nothing has changed, forcing me to restart and start in Normal mode.
That's basically when i realised that something might be seriously wrong, and since i have little understanding of operating systems, i don't know what to do either. Ive tried some tips from other, such as reducing the amount of things it loads on Start up, but it hasn't helped either. The hard drive is relatively fresh, over a year old, but there seem to be no such related issues. Im able to work on the PC, play games and what not, but the occasional ''lagging'' spikes( slow openning, etc.) are extremely painful to watch and experience.
Any guidance would be highly appreciated. :):)