Windows XP by default will remember 400 different folder settings. If you have
more than 400 folders on your system, then they will start to loose their
settings at random. Got lots of folders? Have unique settings? Want to set XP to
remember settings for 1000 folders?
Hive: HKEY_CURRENT_USER
Key: Software\Microsoft\Windows\Shell
Name: BagMRU
Type: REG_DWORD
Value: 3e8
You can set
it to less by varying the value setting.