I installed the attiny45. zip file and created a folder named hardware , and followed all other instructions.i do not see attiny45 board in my arduino ide box. i am using Ubuntu Linux.
created a folder named hardware
Under what directory?
usr-->share-->local-->Arduino-->hardware
boards.txt file should be here...
usr-->share-->local-->Arduino-->hardware-->attiny45
Core files should be here...
usr-->share-->local-->Arduino-->hardware-->attiny45-->cores-->attiny45
After placing the files in the correct directories, you will have to restart the Arduino IDE.
I suggest using a more recent core.