The TravelMate TMP645-MG has a better storage medium than most comparable spec laptops that came out around the same time as it. This portable PC has an SSD storage media, whereas most portable PCs that were released more than two years ago have an HDD storage media. Solid State Drives (SSD) store data in semiconductors on a circuit board rather than using magnetic or optical media. Solid State Drives have no moving parts which makes them very fast and reliable.
This laptop's storage medium (SSD) is actually the best storage medium amongst all laptops of a similar type and age to the TravelMate TMP645-MG.
The worst storage medium amongst comparable types of laptop is HDD.