Earlier i had run the de-fragmentation tool (Piriform, Defraggler) on all my drives in my Laptop. From then onwards the audio in my laptop is not working. I generally get a red-crossed symbol in my audio speakers button on the right hand task bar of my laptop. Occasionally at times the audio is working. I am not being able to figure out what might be the reason for the malfunction of my audio. Please suggest me some solutions if any in this regard.