I have had numerous updates fail and I have no idea why, i've done a few methods such as using FixIt, sfc /scannow and checksur and nothing has worked so far, i'm running windows 7 64 bit,
If the file is too large (8MB compressed), remove the older CBSPersist cab files until the final file is below the limit - you can always post them separately after zipping them. (the forum doesn't allow the upload of bare CAB files, for a number of reasons)
Please also post the C:\Windows\windowsudpate.log file
My Computer
Computer type
Laptop
Computer Manufacturer/Model Number
Asus K52F or Lenovo B51-80
OS
Win 7 x64 Home Premium (and x86 VirtualBox VM)/Win10
CPU
i3 370M/i7 6500U
Motherboard
Asus/Lenovo
Memory
8GB - finally :)/8GB
Graphics Card(s)
it's an i3, dude!/dual Intel&nVidia
Sound Card
onboard
Monitor(s) Displays
15.6" built-in
Screen Resolution
1366x768/1920x1080
Hard Drives
750GB Seagate internal
Sundry external drives attached to other computers on the local network
1TB SSD on the Lenovo
PSU
n/a
Internet Speed
as much as I can get - usually on a dongle/phone, so <1MB/s