BSOD occuring randomally with latest error iusb3xhc.sys

Hi I have a POS computer custom built about 16 months old where I have started work recently
It has a pharmacy dispensing Program and POS program as well which is used in over 600 other places in New Zealand and on the 4 other computers in this pharmacy with no problems. It reboots every day and sometimes at night, when I first looked at it the BSOD gave a error : driver _irql_not_less_or_equal and code usbser.sys. I have endeavoured to update all the drivers and now I get a error which has changed to isub3xhc.sys. I noticed when I update the USB drivers the BSOD appeared and I had to restart.
I will post the specs below. It also has one Samsung reciept printer , one eftpos pin pad Ingenico and two identical Zebra LP2844 printers attached , one for car code labels and one for prescription labels

any clues would be much appreciated or maybe a reform might be in order
computer details as below and I attach the DM log file as well
thank you very much in advance
Operating System
Windows 7 Professional 64-bit SP1
CPU
Intel Core i3 4130 @ 3.40GHz
Haswell 22nm Technology
RAM
4.00GB Single-Channel DDR3 @ 798MHz (11-11-11-28)
Motherboard
Gigabyte Technology Co., Ltd. B85M-D3H (SOCKET 0)
Graphics
SyncMaster (1680x1050@60Hz)
Intel HD Graphics 4400 (Gigabyte)
Storage
119GB ATA ADATA SP900 SCSI Disk Device (SSD)
Optical Drives
ASUS DRW-24D3ST SCSI CdRom Device
Audio
Realtek High Definition Audio
Operating System
Windows 7 Professional 64-bit SP1

it is your Intel(R) USB 3.0 eXtensible Host Controller Driver, first try updating the driver, here's the link:
Intel® Download Center