Dear All
My update on the problem, nothing is wrong with my PC, The power socket which I am using was the source of the problem, on a multi meter when I use the problematic socket out let i can get about 35Volts on the PC Box, while using another socket out let the reading on the voltmeter is close to zero if not zero volts.
losses;
1- PSU under warranty
2- new UPS APC US$150
3- Service Charges US$30
4- ?? for the chargman who will check and rectify my socket outlet

I appreciate your help and advices which led me to solve a problem
Ahmed