Hello! I have an Samsung Galaxy Tab of seven inches. I tried to downgrade from 4.0.4 to 2.3.4 because I couldn't see the flash content because of the restriction of Adobe. But when the flashing stopped, after reboot my tab has stuck on the samsung logo screen and doesn't go to the welcome screen like the other times. Also, during the flashing my tablet writes: -Updating application... E:failed to mount /data (Invalid argument) E:Install_application_for customer: Can't mount /data your storage not prepared yet, please use UI menu for format and reboot actions. Copy application failed. The guide that I followed has the right below steps: 1. put your tablet at download mode and choose Re-Partition,Auto Reboot and F. Reset Time. 2.open odin and choose the PIT site and put the .pit file and choose again the PDA site and put the .md5 file. 3.Press start to begin the flashing. 4.Put again your tablet at Download mode but this time choose only Auto-Reboot and F. Reset Time. 5. Choose the PDA site and put the dbdata folder. 6.Press again the start button to begin the flashing. 7.Put your tablet on the Recovery mode and choose in order wipe cache and wipe data/factory reset , agree to the question and then choose reboot to re-open your tablet. I tried to flash my tablet with some other roms but I have the same result. My tablet remains stuck on the samsung galaxy logo. Also, I observe that my tablet after the first flashing, doesn't go to the samsung logo screen but it appears the recovery mode screen ,which I had to put at the seventh step. a.Could somebody inform me who to resolve this problem? b.How I mount my tablet and what is the tool about it? c.If I leave my tablet black how then I can re-install my favourite android rom in my tablet? d.How I can erase all data of my tablet and what is the suitable tool about it?