@OP:
Nice taste in Music! I saw them live at the Hollywood bowl in 2001. Til Lindemann set himself on fire while singing the song Rammstein, and just stood there burning whilst singing (he was obviously wearing some hardcore gear for that). What an epic show!
Anywho....
As BK pointed out, the SuperFetch service is what you're after.
To Biker's point, ReadyBoost is not a 'fix all' for performance issues. If you have a PC with only a spinning disk drive, and a small amount of RAM, then you may see some improvement as more things are opened.
On the reverse side of that though, if your PC does NOT need to use the ReadyBoost, it shouldn't slow anything down by setting drives up for it. If the PC never needs it, it's not going to use it.
The one note of caution would be to make sure that you're using your fastest USB port. Most devices (depending on manufacture date) have a few different generations of USB ports (e.g. 1 & 2, or 2 & 3). USB 2.0 should be considered a minimum requirement IMHO.
Here are some other things to keep in mind.
Good luck