well... Maxtor died back in the days of when HDDs could only push out ~40MB/s. Your average modern HDD can do ~120MB/s without a problem. So yes, expect ~3x increase in load times and file transfers.
This will not affect gaming performance, only load times and file transfer speeds. If you want to increase game performance you need to up your CPU, RAM, and GPU. If your computer comes with a maxtor HDD then I can guarantee you that your computer is outdated. I work at a computer refurbishing company where we put computers together for underprivlidged families/individuals, and while we are pretty cheap, we would never be so cruel as to use a computer as old as yours... which should tell you that it is time to upgrade
If gaming I would suggest a minimum of a Pentium D, and preferably a Core2Quad or newer. Such systems can be found online for well under $100 today (~$75), and will just need a fresh copy of win7 ($100), and a decent GPU ($100), just make sure that it has a minimum of 4GB of RAM (~$25 upgrade) and you will have a decent (all be it not impressive) $300 game rig.