Move / svn-move file to another folder in TortoiseSVN: How
If you want to move some files from one folder to another in Tortoise SVN. You should not do normal cut paste, or delete, then add new. It will delete the Version history associated with the SVN. so do the SVN move.
Select the files you wish to move.
Right click and drag the files to destination folder
A window will popup appear like following. Click "SVN Move versioned item(s) here"