Bizzare caching issues

[Mordax]

I'm developing something for work and the computer they've given me to develop with must have some really bizzare settings on it somewhere

There are images that I replaced on the server days ago, the PC has been rebooted several times since then, the cache has been cleared out, I even went into Temporery Internet Files and deleted everything including the hidden and system files by hand

The images no longer exist on the server, and no longer exist as far as I can tell on the PC in question, I've checked every hidden chaching location I know of

Yet Internet Explorer 7 still displays them in place of the images that actually exist

As would logically be expected, doing precise positioning with images that I can't see is very difficult, I'm dissallowed from connecting my laptop up to the network to look at the pages in any sort of sensible browser and there isn't another PC without the ancient cached images available for me to use

Where the heck is IE getting these images from and how do I kill them?

Edit: I have fixed this by typing the image addresses directly into the browser window and CTRL+F5ing them, thus forcing IE to renew it's cache for those images

I'd still love to know where the heck its keeping them