Our Linux pals keep application software on one partition and data on another. It's somewhat less convenient to do this with MS products but it is do-able, just don't forget to learn about shadow volumes and such. Then, if you have to take your computer through customs, save your data partition in encrypted files in the clouds, on encrypted optical disks that you mail to your destination or both. Then over-write the data partition with a military-grade file shredder. If the computer gets checked, it is for all intents and purposes a 'fresh' install. They may still keep it, but your data is likely to remain opaque plenty long enough for your patent application to be registered or whatever, and that's what you want.
