Blue file and folder names indicate a XP compressed file. Either you used Disk Cleanup and chose to compress old files, or someone specifically compressed the files. It is not a good idea performance wise to compress an entire drive, but letting Cleanup compress old files doesn't hurt anything since they are infrequently used. Still not sure it is practical unless a person is very low on hard drive space, and even then with the price of large drives it would probably be smarter to add a drive or replace the existing drive with a larger one.
