Updating to itunes 11.1.4.62 Install failed on W8.1

Hello,

I tried to update my Itunes to 11.1.4.62 this morning, and it failed.

I followed the instructions and downlaed it from the Apple website and ran it... it failed again.

When I then tried to open Itunes, it failed staying multiple DLLs where missing.

I had to un install every apple program on the Pc and tried the itunes dowanleded install again... it failed.

I got hold of the pervios version, and it installed without a problem. I tiy to run the update again ... it failes.

( it "loads new files", gets to the get of the progress bat, then "rolling back", then the failed message.

iTunes Installer Completed.

The installer encountered error before itTunes could be configured

Error occured during installation. Your system has not be modified

Please run the installer again, or click finish to exit.

Then I open the previous I tunes, I couldnt open it as the iteuns libaray file was created by a newer version of itunes and therefore wil not load.

I renamed the file and tried again, itunes opens, but I cannot add my music or open the itunes tore, and itunes crashes.

Ive de-authorized the PC, and re-authoried it again, Itunes Crashes

Windows event logs shows an error :-

Faulting application name: iTunes.exe, version: 10.7.0.21, time stamp: 0x504d85d9

Faulting module name: iTunes.dll, version: 10.7.0.21, time stamp: 0x504d85b5

Exception code: 0xc0000409

Fault offset: 0x00fa1eab

Faulting process ID: 0x2480

Faulting application start time: 0x01cf2120f2afa332

Faulting application path: C:\Program Files\iTunes\iTunes.exe

Faulting module path: C:\Program Files\iTunes\iTunes.dll

Report ID: 4d722fdf-8d14-11e3-b058-001921394ac7

Faulting package full name:

Faulting package-relative application ID:

PLEASE, can some either help me upgrade windows, or get the version version working again ?

Thanks