Data Loss Problem ?

Please read this carefully and please answer me , I have always had this problem , I loss display , the screen display and I could hear the PC still running and then I had to restart , sometimes when system starts up after restart I get ( the System has recovered from a serious Error r) message and sometimes I don't get it , I recently formatted my PC and reinstalled windows , before I connect to the internet I have only installed kaspersky AV 7 and updated it before I didn't anything , then I have downloaded some photos to a folder in my desktop , I visited only 4 webs that I completely trust and I didn’t run any (exe) files or open any-mails or click on any links whatsoever .Then I ran a full PC scan with Maximum security setting , scanning all files and riskware detection enabled as well as proactive defense ,( No Threats Detected ) was the result and then I saved my files on a CD , until now everything was completely Normal and my system is 100% fine , I have moved the folder from ( My desktop) to my local disk D. then the problem that I have explained earlier occurred , the display was gone and I had to press restart , when I restarted , the system did a routine disk check , and I read something about like : ( The Entry will be truncated ) or something like that , the system started up normally but when I wanted to check out the files , they were gone ! nothing in Local Disk D. but system restore information folder , recycled , and a folder named Found 000 which contains some fragments of files found when scanning the disk . I have restored my data from the CD that I made , but I need to know what cause this data loss ? is it a hardware , software , system failure or is it an infection ? I'm kind of worried , detailed explanation would be much appreciated