This worked for me:
By default, Windows XP will remember the view settings for the 400 most recently
used folders. After that, XP will begin overwriting the data of the oldest folder,
and its view setting will be lost. The information is stored in the registry by two
keys:
HKEY_CURRENT_USER\Software\Microsoft\Windows\Shell
and
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam
These keys can be modified to make XP remember more folder settings.
1) Open Windows Explorer and go to Tools--Folder Options--View--Advanced Settings. Ensure that "Remember each folder's view settings" is checked.
2) Open Regedit and go to HKCU\Software\Microsoft\Windows\Shell. Right-click on "Shell", then follow to New--Key--DWORD Value. Name this item "BagMRU Size" (without quotation marks, but with a space between BagMRU and Size). Double-click BagMRU Size, give it a Decimal value of 5000, then click OK.
3) Now go to HKCU\Software\Microsoft\Windows\ShellNoRoam. Create another BagMRU Size DWORD Value for "ShellNoRoam". Again, give it a Decimal value of 5000, then click
OK.
4) You will have two "BagMRU Size" values equal to 0x00001388 (5000).
5) Close the registry and reboot.
Windows XP will now remember 5000 folder view settings instead of 400.
Thanks to Fred Nava of the Windows Shell Test Team!
If you have installed SP2, however, these settings will already be there; MS finally took care of the problem.