The easiest way to change the dpi is:
Boot your phone back into windows, and hook it up to the computer.
Go to your android folder on your sdcard (if you kept default it's hyperdroid1.1 folder). Inside there, go to root, then to system. You'll see a file called build.prop. Open this file in a text editor and look for the line ro.sf.lcd_density=(whatever number it is). Change this number to whatever you want it to be, disconnect your phone from the computer, and boot back into android. The changes should be applied.
(If you're having trouble finding the line in the build.prop file, it's right under the Additional Build Properties section, should be the first one under)