A week ago I posted about Internet Explorers's scaling of graphics on my widescreen Dell. The problem comes when IE draws images, IE scales images upwards. For example;

IE6 sample Mozilla sample
Internet ExplorerMozilla

Whilst going through the new Microsoft blog entries last night (RSS feed) I read Omar Shahine's post on his new high density display. He points to an MSDN article on DPI, which contains the registry tweak which controls IE's scaling. The article reveals that the IE tweak affects both text and graphics scaling;

Internet Explorer 6 and later solves these problems by proportionally adjusting the scale on displays with higher resolution.

When scaling is activated on a 192 dpi system, for example, an HTML element that has a specified height and width of 250 pixels has a scaled height and width of approximately 500 pixels.

192 DPI / 96 DPI * 250 pixels = 500 pixels

So this explains why images in IE look bad. There was hope however, the article also gave the registry entry which controls the scaling tweak;

HKEY_CURRENT_USER\
  Software\
    Microsoft\
      Internet Explorer\
        UseHR=dword:00000001

If you delete the key or set the value to 0 and restart any IE instance you have open scaling no longer happens and graphics look like they were supposed to. You may find that because text no longer scales up that some web sites, especially those with fixed font sizes specified in pixels are not readable. Another Microsoft blog has a fix, Tony Schreiner documented a way to add a context menu option to increase font sizes.