dannylivesforher :
No,I don't think so.Because if something was loose in it's slot,the system wouldn't turn on or boot up. But you said it booted up and it restarts only after a few hours. So it must be the problem with one of your components,like the RAM or PSU. The probability is your PSU not being able to supply necessary power. Could you provide detailed info about your system? Including the PSU,GPU,MB,CPU etc ec...?
here are the parts in my computer:
processor: AMD FD6300WMHKBOX FX-6300 6-Core Processor Black Edition
graphics card: EVGA GeForce GTX650Ti Boost
motherboard:ASUS M5A78L-M LX PLUS AM3+ AMD 760G Micro ATX AMD Motherboard
power supply: Corsair Builder Series CX 430 Watt ATX/EPS 80 PLUS (CX430)
CPU cooler (replaced the one that came with the processor):Cooler Master Hyper T4 CPU Cooler with 4 Direct Contact Heatpipes RR-T4-18PK-R1
RAM: Corsair XMS3 8 GB (2 x 4GB) 1333 MHz PC3-10666 240-Pin DDR3 Memory Kit CMX8GX3M2A1333C9
hard drive: WD Blue 1 TB Desktop Hard Drive: 3.5 Inch, 7200 RPM, SATA 6 Gb/s, 64 MB Cache - WD10EZEX
Disk drive Asus 24x DVD-RW Serial-ATA Internal OEM Optical Drive DRW-24B1ST (Black)
Case Corsair Carbide Series Black 300R Mid-Tower Computer Case (CC-9011014-WW)
i am also using a wireless network adapter: Netgear WNA3100, it seems to stop working after my computer shuts itself off.