My PC keeps dead locking / resetting and I have to hard power down to get out of it. It happens at random and I am at a loss as to why. Also my harddrives will occasionally make a high pitched click click once and a while. Like plastic hitting a fan. I've worried about this thinking it could be a hard drive failure, but both of them? Also using Crystal Disk has shown no changes in their partitions etc. I have done the following Attempted fixes: Replaced the motherboard (RMAD) Replaced the CPU (RMAD) Replaced the GPU (Swapped to a different maker and brand then back when it still froze) Replaced the Hard Drive (I have two hard drives. I took my second drive reformatted it fresh installed windows updated a bunch and it still froze) Replaced the PSU Mem Tested and Replaced RAM with a totally different brand . Updated to latest version of BIOS Taken it into an IT shop. They thought it was overheating and "fixed" it meaning they probably cleaned it out. They only got it crash once at their shop in a week period. I would take it back again but I live in the city and have no means of transportation. Winter makes it especially difficult to get my system over there. I don't know what is causing it My temperatures turn up fine. Nothing really goes over 50C for the most part. My CPU at 100% load is like 83C The problem happens when I'm idling or when I'm playing games / doing work. I have replaced every part! I'm not getting any kind of BSOD warnings or anything. I went as far to theorize that it may be brownouts or power issues so I even put my computer on a power conditioner still no luck. The incidents started occurring at random around late August. I have had this computer for a year.I built it around august of last year. This problem was frequent then too. I thought replacing the motherboard had solved it. I left to visit my family for the holidays and when I got back after new years no problems were apparent. Until it started back up again in August. (Most likely just a coincidence but still very strange.) At this point the only things I haven't changed or swapped are the keyboard, modem, and the case itself. Could driver conflicts be causing this? I'm curious as I've tried to figure out how to update my USB ports as windows seems to tell me to, but never have any luck figuring out what to download for those. -- Operating system: Windows 7 Professional (legitimate copy) System specs: Custom PC: Motherboard: ASUS P8Z77-V LX LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard RAM: Corsair Vengeance Blue 16 GB (4X4 GB) PC3-12800 1600mHz DDR3 240-Pin SDRAM Dual Channel Memory Kit GPU: EVGA GeForce GTX 660Ti SUPERCLOCKED 2048MB GDDR5 DVI-I, DVI-D, HDMI, DP, SLI Graphics Card CPU: Intel Core i5-3570K Quad-Core Processor 3.4 GHz 4 Core LGA 1155 - BX80637I53570K Power Supply: Corsair CX750 Builder Series ATX 80 PLUS Bronze Certified Power Supply Case: Antec Dark Fleet DF-35 If anyone can help me solve this nightmare please. It has crippled my ability to use my computer for work, entertainment, and just general usage. I'm living terrified that my computer will freeze and I'll lose all my data. Fortunately I've backed it up, but still its an unsettling feeling. Whoever figures this out is no doubt king of the IT is all I can say. Most people I have talked to are as clueless as me. I mostly hear to just build a new PC. However the thing is a year old and I"m not made out of money!