GSM-Forum - hard drive problem in N91

hi ..
i m using nokia n91 and got a problem in the hard drive..
while proceedign with formating it says hard drive unavailabke however if i connect my phone to pc there are mainly three options to log on the pc from phone "media Player", "PC suite Mode" and " Mass Storage"
only pc suite option is available while proceeding with other options the phone displays an error "Hasd Drive is being used by other source"

the problem occured while i was transferrring data to my phone from pc and it got stuck i restarted the phone and after restarting it didnt connected in mass storage and media player mode i tried *#7370# and after when restarted it proceeds with an installation process which further interuppted by an error "untrusted software found on hard drive, complete installation from file manager"

there in the file manager a file is present with the name "bcd0000.sis" with a not installed status proceeding installation process it shows that its a file of an Apllication "xplore" which i installed earlier without signing and cracked it with a key generator however it was running successfully. installation proceeds and after the complete process of installation the error comes "corrupted file"

i tried installing the original file of xplore but it didnt proceeded and displayed an error "required application access not granted"
and now there is a font file in the application manager with an installed status however after removing this font file a new file appears with a name "a000017f.sis" with an uninstalled status andon reinstalling it proceed successfully and displays in log "test font" with an installed status.

plz help me to get rid of this problem i am unable to install any kind of applications and unable to use the mass storage mode and media player mode while connecting to PC.:confused: