Ok I'm being paranoid here! I'm the only one who uses this PC so it's easy for me to keep track of files and settings etc. I kinda have a habit of regularly checking the number of files in directories (like the DIR/OD/A/S command -- list all files inc. hidden in date sort) and seeing if anything's been modified or deleted. I know there's special programs to track installations but I just do CHKDSK before and after and see the difference in the folders, hidden and user files. I then count the number in the folder created for the new app and it's subdirs, etc, and look for new files in the DESKTOP folder and Start Menu folder. Sometimes some files are added in c:\windows and c:\windows\system. In the total adds up I'm satisfied. I sometimes do Find All Files and sort it by time/date for 1 day. If the installation produces files which aren't new (i.e. today's date) then you can find it hard to track them down. Anyway back to point, I've scaned for viruses, trojans, malware, etc but is there any virus or something which could randomly delete a file from anywhere on your HD? I have scraps of paper with today's date and time and chkdsk give this output for records!