I use several computers, with different operating systems too. I have personal files on all of them and never remember where they are.
If you have a similar chaos in your computers and you have easy access to broadband (ADSL or more), you might like an online folder fully integrated with your Microsoft and Linux (Ubuntu) operating system.
Search for "dropbox" in your favorite search engine. They offer 2GB of online storage, backed-up. Files will be downloaded (sync'ed) to all your installations. So you have them online and on all your computers.
If you complete few steps you can receive 4x 250MB, for a total of 3GB of storage.
You can get your first extra 250MB if you subscribe through this link (I get 250MB too).