there are apps out there that will allow you to decrease the lag time of pop up menus and the start menu. Theres no way with your pc you should see a visable lag time because of window blinds. I have a P2 450 64meg radeon and 384meg ram... no visable delay. adjust that setting and you'll be fine.

There are programs out there that do this for you for eg. ( I don't endorse any of these products just offering them as a possible answer for your needs. ) Tweaking Toolbox, Customizer XP and Magic Tweak just do a Google search on any of them... if your a do it your self sorta guy then edit the registry yourself. Allways back up first. Don't edit your registry if your not familar with it.

1. Start the Registry Editor
2. Go to HKEY_CURRENT_USER \ Control Panel \ Desktop \
3. Right-click the String Value MenuShowDelay, and select Modify
4. Change the Value data (0 is fast, 400 is default. These are all in miliseconds)
5. When ready, press OK and close the registry editor
6. Log off, or restart Windows for the changes to take effect

I honestly do not know what sort of effect a negative value would have had on that setting. When u changed it to 0 logged off and back on again how fast was it compared to what it was b4?