Windows 7 forum: Windows backup failure

i do a weekly scheduled backup it failed (code 0x81000019)this week. i freed up space try again fail. i check the event viewer and the only error even remotely related to VSS is "The VSS service is shutting down due to idle timeout."

i re-tried multiple times (with my security software off and with it on) and checked and the VSS service was on and starting properly

i researched it on the net and ran "vssadmin list writers" (from an elveated command prompt of course)some of them listed time out error i reboot run it again and all have no error then try the backup and the same ones have time out error
i'm currently running "sfc /scannow" because the research on the internet said that one of the causes could be corrupted drivers

my backup drive is a usb HDD drive f:/
interesting event viewer logs for my backup drive
"The shadow copies of volume F: were aborted because of an IO failure on volume F:."
on top of this the drive won't recognize unless turned on after the boot is finished or off then on again once the desktop is displayed its the same regardless of what cable i use and check disk shows no errors on the drive(haven't done surface scan yet)
i will post the results of sfc /scannow

system information
windows 7 ultimate 64bit
8gb ddr3-1333 ram
500gb sata internal hdd c:\
500gb usb external hdd f:\
athlon IIx2 3ghz
msi 1GB radeon hd 6670
msi 880g-e45 motherboard
lg sata internal dvd-rw drive
sata controller in ahci mode