@shardul ive done all that what you told me nd i got this :
Nokia-N900:~# nitdroid
************************************************** ********
* *
* This installer will automatically download and install *
* NITDroid, an Android port to Nokia N900. *
* *
* WARNING! *
* THIS PROGRAM WILL INSTALL APPS ONTO YOUR DEVICE *
* AND FORMAT YOUR MICROSD WITHOUT ANY WARNINGS. *
* THERE IS A SLIGHT RISK THAT THIS WILL RENDER YOUR *
* DEVICE UNUSABLE, REQUIRING FULL MAEMO REFLASH. *
* *
* PLEASE BACKUP YOUR DATA BEFORE PROCEEDING *
* *
* YOU HAVE BEEN WARNED *
* *
************************************************** ********
Type 'YES' if you accept the terms and take the risk >YES
you have to format your micro sd card, then go to xterminal type umount /dev/mmcblk1p2
If again problem comes then open the attachment and install in your n900, It will smoothly update nitdroid installer and without any problem you will be able to install nitdroid
