How do I get rid of long load times when loading the single player map list?

I am getting long load times when I try to load up the single player map list when creating an AI game, when I load up the same list, or presumably the same list, when under multiplayer it loads in seconds, single player I have clocked up to two minutes. Is anyone else experiencing this issue? I only have a dozen or so custom maps downloaded, but I have experienced this behavior since the beginning. I do get some long load times, around a minute, when loading up missions during the campaign but nowhere near the wait of trying to load that list. I assume that my mission load times are due to my harddrive being slow, my de-fragmentation and system checks run nightly. I do have Defender and Kaspersky running but they are approved applications for each.

Solution 1:

Though it doesn't take too unbearably long for me to load the "Play Versus AI" map list, it takes significantly longer than loading the multiplayer "Custom Games" list.

As a work around you can also create single player games against AI from the multiplayer screen. If you choose "Custom Game" and only add AI opponents you basically have a single player game against the computer. If you are heading for the various achievements for playing against AI opponents you even have to create the game this way. For "Play Versus AI" games there will be no achievements awarded.