It really doesn't make any sense to partition your disk like described above for performance reasons. If you had two separate hard drives, that might increase performance. I seriously doubt that your problems are partition-related though. Still, if you want to try it for yourself, go ahead. The easiest way I know of to do it is to use a Linux utility called GParted. You can download and burn a bootable CD that will allow you to change, add, delete, shrink or enlarge partitions at http://gparted.sourceforge.net/livecd.php .
It is very simple to use. Once you have burned the file to a CD, boot your computer from the CD and answer the questions the program will ask you. You can then make choices using a graphical user interface. If you are running any version of Windows above Windows 98, I would suggest using NTFS as the file system. You can also use the FAT32 file system as well. Make sure to defragment your Windows installation prior to running the utility.