There can be a problem with windows causing programs to freeze and eventually crash. This is my experience. With a number of programs(FTM, MS Office etc), not only with copy and paste but also with various file commands such as <save as>, <open> will freeze or crash. The problem appears if you have changed the default location of where Windows saves your <My Documents> folder. When you originally set your computer up Win 7, Vista, and from memory XP as well, creates the following file structure. C:/Users/MyName/My Documents/Family Tree Maker I do not store any data on my C:/ drive but have changed the location of all my documents to an external USB 3 drive G:/ When a command is executed and the OS looks for your data to open, save,copy paste etc it looks for the file in C:/ drive if it cant find it, it then freezes. This does not always happens with me but it is intermittent. For example I cannot attach a file to an email in Thunderbird by the normal method TB just freezes. The only way I can do it is to drag the file from windows explorer to the email window. FTM freezes if I try and create and save a gedcom with all people in my file(11400 approx individuals) My Computer is i5 processor 16GB Ram, SSD C:/ drive and dual 21.5inch monitors running win 7 64 bit pro Peter