under the cleaner heading of the software,if i click all the boxes in the 'ADVANCED' section and clean my system-is there any problem i may face in terms of normal operations of the computer.am asking this 'cos am a computer novice.i don't want do anything which hampers my day today operations.at the same time i want to clean my comp with all the junk.

Hello jois and welcome to the forum

It is not really a good idea to use the advanced section of any software, even CCleaner unless you know what you are doing. It is safer to stick to the cleaning defaults until you have gooten used to things.

Have a read of the CCleaner documentation here first.

http://docs.piriform.com/