Arduino Bootloader Error

Hi guys,
i recently bought a Arduino Uno board and when i first tried to upload a program, it shown an error wich says: "avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x3d", i've tried to re-install the drivers, the IDE, then i've tried to burn the bootloader and it didn't worked, i've read that if the "L" Led in the board doesn't blink it means that the bootloader is damaged or deleted. How can i re-upload the bootloader or reset it?
Thanks in advance

What are you using for a Programmer? A Programmer connects to the ICSP header to access memory directly and install the bootloader (and change fuses).

Hi, i haven't got a separate programmer, i've got only the board