Windows 7: Annoying problem - COD4 patches refuse to install

Hi all. Yesterday I decided to revisit COD4 after some time not playing. I installed the game and it played fine, but I wanted the patches to get all the maps, updates and interconnectivity with other patched players (i.e. the vast majority).

So I downloaded all the patches from gamershell and tried to install them, in order. The first patch contained only an iw3mp file (I downloaded from another website also, and it was the same). I copied the file into the MW directory and overwrote the old one. Game still played fine, version now reading 1.1.13(etc).

Then I tried to install patch 1.2. The installer got going fine, I input the target directory etc. but the moment it got to actually copying and updating files, it stopped with "Error 2 - The system cannot find the file specified". Same story for all other patches. I tried reinstalling COD and running the patches without replacing iw3mp from 1.1, still didn't work.

I only found one other instance of this on google, which was unsolved. Any help appreciated .

EDIT: Also tried compatability mode with Windows XP SP2 and SP3 and with Vista, which didn't work.

Assuming you have the boxed retail version here are 1.4 through 1.7 patches
CoD4 Central | CoD4 Patch | CoD4Central.com | Your Main Call of Duty 4 / World at War / Modern Warfare 2 Source.

1.1 Download Call of Duty 4: Modern Warfare v1.1 Patch
1.2 Patches and Fixes: Call of Duty 4: Modern Warfare v1.2 Patch - Demo Movie Patch Download Section - GamersHell.com
1.3 News: Call of Duty 4: Modern Warfare v1.3 Patch - GamersHell.com

good luck