after building up the database of my tunes under itunes most of songs became PECGV or something rather.
Yeah, iTunes does that. It gives all your songs silly names like ADHS.mp3, 43UD.mp3, etc. If you want to keep using iTunes and Rockbox simultaneously, you should use Rockbox's database feature, which allows you to navigate your music by it's tags rather than filenames.
i then proceeded to uninstall Rocbox using the windows auto installer/uninstaller. things seem to go fine till i pull it out & rebooted. the screen i got is this black screen with the following words...
You're nowhere near being fawkkk'd. There are two parts to Rockbox - the
bootloader (what's giving you that nice message there), and the
build (".rockbox" directory on your disk). So try uninstalling the bootloader (either with Rockbox Utility, or the manual process documented in the manual). You should also still be able to boot into the Apple firmware using Rockbox's
dual-boot feature.
Oh, and for disk mode, after you reboot with menu+select, while it's booting up, you have to hold select+play.