I have a VAIO laptop which has not been working as expected recently.
At first, I had the Blue Screen of Death coming after some minutes of working with Windows and a crash dump. I used to ignore it since it restarted windows whenever it happened and it wasn't too frequent: about two-three times a week.
After a month the computer became very slow and I couldn't work with it any more.
I re-installed Windows 7 Home Premium again, but after a day it became as slow as before. I tried installing windows 8, but it was the same. I finally installed Windows 7 Home Premium while formatting and deleting all partitions during installation.
Now after four or five days, again there are problems and today the Blue Screen showed up again. chkdsk found 0 bad sectors. I also tried system start-up repair the second day after installation.
I don't know what is wrong with my laptop that a fresh installation cannot fix the issue.