I've downloaded the ATtiny13 core files for Arduino
From where?Use this one instead:https://github.com/MCUdude/MicroCorePlease use code tags (</> button on the toolbar) when you post code or warning/error messages. The reason is that the forum software can interpret parts of your code as markup, leading to confusion, wasted time, and a reduced chance for you to get help with your problem. This will also make it easier to read your code and to copy it to the IDE or editor. Using code tags and other important information is explained in the How to use this forum post. Please read it.
But still the same error
The virus PC is the cause of error?
Did you select the MicroCore board from the Tools > Board menu? MicroCore definitely does have recipe.preproc.macros defined.Definitely not. The problem is most likely that you installed a very old hardware package that is not compatible with the version of the Arduino IDE you're using. I can't say for sure because you didn't say which package you installed originally or where you got it from.
Please post the picture here. I don't want to visit some random website.
Please see the Picturehttp://forum.arduino.ir/4/12/3348.html#post16540
You're still using the old ATtiny13 package that you originally installed, that's why you're still getting the same error. If the MicroCore board isn't showing in the Tools > Board menu then the old package may be interfering with MicroCore, please uninstall the old package and then restart the Arduino IDE.
Files related to the attiny45, attiny85
STMicroelectronics IC core for Arduino. There is?
How disable the divide clock by 8