A bit more info on the two utilities and the data collected for ReadyBOOT.ETL [btw, disabled with a SSD seems moot as stated in this quoted thread, inadvisable with a slower HDD]. There is a difference between ReadyBoost and ReadyBoot. On systems with more than 700MB of RAM, ReadyBoot uses data from 5 previous boots to create a plan for a boot-time memory cache. Similar to Windows XP prefetcher, it will try to preload files into RAM before they are needed.