thanks for the response. I have done what you have told me to do but my problem is still the same. The first time I use the sfc /scannow, it detects some problems at first scan and said that the systems resolved some issues in the system encountered. The next 2 scans says "Windows Resource Protection did not find any integrity violations". What should I do next?
Yes, I have 2 anti-virus software installed. the avast and microsoft security essentials. Does this affect the system? as I have said earlier, I run a full system scan using these softwares and they both says "no threat found".
thanks in advance!