Hi, my PC has been acting sluggish the past few months and it's only gotten worse. I re-upped my Avast subscription to help clean up the clutter and optimize it. So after that I was having trouble closing the few windows I had up (Chrome tab, Powerpoint, and Notepad) and decided I'd restart it to see if that remedied it. After it shut down I went to power it on and it started then shut off (which has been a regular occurrence since I built it 5 years ago, it will normally boot on the second try) but it just keep turning off and then immediately back on. I opened it up and noticed that the CPU LED was red for the few brief seconds it was on and have consulted my manual but outside of telling me the LED exists, I can't seem to find out what might be the culprit and how to fix it. I did notice in task manager before I turned it off that the HDD was at 99-100% even though there seemed to be nothing using up any memory. Is there anything I can do here or is it time to upgrade? Sorry, I'm not incredibly PC savvy and only really read enough to pick out my parts and put it together (sorry if that is taboo here). Any help would be appreciated, thanks.
Motherboard: Asus Z97-A
CPU: Intel Core i5 - 4460
GPU: EVGA Geforce GTX 960
PSU: Thermaltake Toughpower Gold 750W
RAM: 4GB (x4) GSkill Sniper (though I've been suspicious of one of the ports not actually working though never checked)
HDD: WD Blue 1TB
Motherboard: Asus Z97-A
CPU: Intel Core i5 - 4460
GPU: EVGA Geforce GTX 960
PSU: Thermaltake Toughpower Gold 750W
RAM: 4GB (x4) GSkill Sniper (though I've been suspicious of one of the ports not actually working though never checked)
HDD: WD Blue 1TB