i didn't do anything.took out the battery. put it back in and it just doesn't boot.
I can't think of any solution to this problem as there isn't enough material you provided us with.
What ROM was running on it?
Rooted or not?
What caused you to Reboot your device?
Which software/application you installed before restarting the device?
Is that a i9000 or any other model e.g Vibrant?
Does it go in Recovery Mode?
Anyway I have resetted my device and finished installing the apps too. Now I need some software to backup these softwares, I know about Clockwork + Titanium but they both require root, which I haven't done.
Without Rooting, you can't exactly make PROPER backups.
Titanium Backup is THE BEST software available for Backing Up your data.
So Root your device Pronto.
Also, that Clockwork Recovery Mod wala "backup" is called a NanDroid Backup, which is just like a Backup
Image of your ROM. (like you create images of Windows using Norton Ghost or BartPE)
how much time does i9000 takes to charge when battery is at 0%
wall charger was way too slow so i connected it to pc and its off still now
3 hours if charged via AC Charging.
If charging from Wall Socket is taking time, then confirm it from the Settings>Status whether or not its Charging at AC.