* look to the PICTURE.
1st: What is the meaning of this SPEED?
2nd: By changing the HardDisk well it become BETTER?
3rd: Do i need to change BOTH or just the Primary/Secondary?
REGARDS
1) That is not a speed, it is a rating that W7 gives your HDD based on its transfer and read/write speeds
2) Yes, but you will need a HDD that is BETTER than the one you have now
3) Yes, I think you would, but I am not sure.
If you really want to increase this score (such as for moving large amounts of Data like you said), then you will either need a Solid State Drive (SSD) or a very fast RAID setup (like zzz2496 mentioned).
An SSD would be the easiest and cheaper option, but they are still expensive. A high quality SSD can cost around $500 for a 320Gb drive. There are some less expensive, but still cost way more than your typical HDD. You could also try getting the Western Digital Velociraptor, a 10,000 RPM HDD.
A RAID setup would be even better, but costs WAY more. zzz2496 knows more about these than I do, but for an internal setup, you would need a $250 controller card, plus the hard drives themselves (preferable SATA III, at 6Gb/s)
The SAN setup he mentioned I know nothing about, so you will need to ask him.
In the end it really depends if you NEED to spend $500 or more just to increase the score. That is up to you, but if you are serious, make sure to get a LOT more information about it, and be sure to run your decision through us so we can make sure it will work like you hope.
~Lordbob