Unfortunately there is no way to prevent people from challenging your Will in a court.

Assuming your Will has been signed and witnessed correctly (as per the instructions that we supply with it), then the challenges are likely to relate to being "fair".

Perhaps you have a son or daughter who you feel does not deserve their "share" of your estate. They may try to challenge the split in court.

Of course you're not going to be there to argue your point, but you can include a statement with your Will where you explain exactly why that person deserves to miss out. This would be a separate document which you sign and date. Keep it factual and not too bitter and twisted.