Ok, thanks Joel. Following your advice I went to my C drive and right there was a folder named "CkM'[6_eLNPZlkSUjo" so I opened it and inside were 8 files of 221,184kb, one of 146,876kb, one of 2kb and one of 1kb. I deleted it and emptied recycling bin. Now I got my lost space back. Is it safe...