u25dts.dll is a DLL file that is used by the Date Time String User Function Library and is created by Crystal Decision, Inc. If you are having a problem with this file then there may be an error in your registry.
Registry errors are not something to be alarmed about. In fact, they are quite common. The thing that can make people nervous is that you can experience a system “crash” which may result in the Blue Screen of Death. This can be fixed, however.
To fix this problem you should try a registry cleaner such as ZookaWare PC Cleaner. ZookaWare PC Cleaner comes from the makers of the ever-popular Spyzooka. ZookaWare are trusted leaders in the industry and have a guarantee that would inspire confidence in anyone – 100% error removal or your money back. Now, who could possibly resist a deal like that?