I am personally not a fan of the desktop cleanup wizard, and i wanted to find a way to manually turn it off. Well, found one, and a way to edit the number of days between showings. First, to turn off the desktop cleanup wizard, open regedit, or regedit32, and go to the key

HKey_Current_User\Software\Microsoft\Windows\CurrentVersion\Explorer\Desktop\CleanupWiz

In that key, there should be 4 values

(Default)
Days between clean up
Last used time
NoRun

Don't pay any attention to the (Default) value, every reg key has one, and for this key it means nothing. The value you are looking for should be quite obious, as it is called NoRun. The Default value of NoRun is 0x00000000 (0), or False, meaning that is will run. To disable it, change that value to a 1, so that it looks like 0x00000001 (1), or True, then it will not run.

If you like the cleanup wizard, and want to change the interval between the days it will show, the go to that same registry key and select the value called Days between clean up. That has a default value of 60, which looks like 0x0000003c (60) meaning every 60 days it will run. To change that, change it's value to however many days you want. You could even have it run every day, if you wanted it to.