So last Friday night I was surfing the Internet and I noticed how unusually slow my system was, this slowness and unresponsiveness all happened very quickly and suddenly. I noticed Firefox would freeze my system for 5-10 seconds when loading some pages, and so would Chrome. Memory usage was nothing of high either. I have 8GB of RAM and even when I run VMs I never max it out. I opened Task Manager and saw that my memory usage was around 30%, and my CPU usage was around 23%. By the time I read the CPU usage the system had completely frozen. I hadn't restarted this system in over a week (it was only being put into hibernation at night), so I decided to do a clean restart since that has helped fixed many issues for me in the past.
When restarting everything seemed all fine at first, Windows booted up at its usual, very quick speed (Windows 8 on a SSD), but after I logged in, I immediately knew something was wrong: the start screen wasn't responding to any input within five seconds, and when I managed to get to the desktop, none of my pinned shortcuts on the taskbar loaded. Windows Explorer was also crashing constantly every 5-10 seconds too, which made navigation harder. After about two more restarts my SSD wasn't recognised any more ("Reboot and select proper boot device" message came up). Immediately I thought the SSD was faulty, but when I went to disconnect the USB drives I had plugged in and then restarting again, I noticed that the system was booting up normally again. At this point I then thought I had some sort of malware infection.
When I managed to get it up an botting again, I managed to get the system into safe mode, and still had the crashing issues there. When I went to do a scan with Malwarebyte's Anti-malware, it threw an error (run time error 13) and then crashed. I also managed to launch CCleaner, and that crashed a few times too. I saw no suspicious startup entries while checking CCleaner.
I also checked the Event Viewer, and slow lots of error reports there for Windows Explorer. I can't exactly remember the details, but I think the hexadecimal code for the crash was 0x8000000a. I'm getting tired so I don't really feel like having to go through the trouble of checking the Event Viewer again tonight.
I also checked the SMART health status in CrystalDiskInfo, and it stated that the SSD was 100% healthy. The drive has had about 900GB of reads and 800GB of writes. The retired block/sector count is only 3 too, as I recall.
I also had trouble accessing removable drives. Since Windows Explorer was constantly crashing, I had to use the command line to try and access drives. I had an alternative file manager on a USB drive (Explorer++), but I couldn't access the drive for some reason ("Device is not ready" error). I tried opening Winrar and 7-zip, and they never started either.
Now I'm getting the unrecognised boot device error message again, and I'm really confused. Windows acts like it's infected with malware, plus the SSD appears healthy in SMART. But the SSD sometimes fails to boot?
Power supply: Corsair TX750M
Motherboard: ASRock Z77 Extreme4
CPU: Intel Core i5 3570K (was overclocked but I later downclocked it back to default to try and see if that would solve my issues, which it didn't)
CPU cooler: Cooler Master Hyper 212 EVO
RAM: G.Skill Ripjaws X 8GB, 1.6GHz
SSD: Corsair Force GT 120GB
HDD Western Digital Caviar Blue 500GB
GPU: XFX Radeon HD 7870 Black Edition
Latest ASRock UEFI BIOS (can't remember the version, sorry)
Windows 8 Pro
Intel Rapid Storage Technology driver