And yeah I read the technical information, but that is too technical I guess.
Can u just tell me adding that file in avast4.ini would have any effect on the performance of avast! ?
You aren't adding a file to/in the avast4.ini file it just changes a setting to cater for how other programs/avast interact the 'system wide hooks' that were talked about in the technical information. These hooks can intercept keystrokes to do things, like open files, etc. and there are some occasions that these hooks conflict.
This however, is more commonly seen in multiple AVs installed as they hook files so that before they run they are scanned and why this question was asked.
As has been said it should have no impact on performance.