Even after that, if your XP still dumbs, the answer is that by default, Windows XP is limited to 200 local folders and 200 network folders, for a total of 400 folders. So that after it remembers for 400 folders, that's it. It's full.
How you can solve this?
This effect only to before Windows XP SP2. So the quick fix would be to download and install Windows XP Service Pack 2. What if you don't want to install Service Pack 2 for some reasons? Read the second way.
You need to edit registry. As always dealing with registry, use it with great caution and use at your own risk.
- Go to Start Menu -->> Run
- Type regedit and press Enter.
- Browse to the following registry key.
- You will see the registry value BagMRU Size in the following pic.
- Double click on that and change the value to 5000. Make sure you select Decimal. After that click OK.
- After that browse to another registry key.
- Change the BagMRU Size to 5000 too.
After you've done editing the registry, make sure you restart your Windows to make change effective. Hey, Windows is not as dumb as you think!
Source : Microsoft