I recently had to change my development to another PC. I installed TortoiseSVN because I still had source code lying around that had still to be checked in SVN. But apparently the new installation of Tortoise does not recognize my source folders, although the '.SVN' folders are still there I see no overlay icons appearing on the files.
Is there a way to remap my local folders to the folders in the repository ?
TortoiseSVN has a setting to use "_svn" folders instead of ".svn" folders (due to an issue with older versions of Visual Studio), check if that's causing your trouble.
Since it's an old work-folder you've recovered from an old system, I would consider removing all ".svn" folders, checkout the code again (optionally from a revision number you remember the working folder was at), and move the old files (without ".svn" folders) over it.
Make sure that the TortoiseSVN installation on the new machine is the same or newer than the one installed on the previous machine. New versions of tsvn sometimes use newer repository formats that older version don't understand.
Does the new machine have a 64-bit operating system? If so, be sure to install the 64-bit version of tsvn. The 32-bit version can still be installed on 64-bit windows but the functionality doesn't show up in the default 64-bit Explorer.
Even though the overlays aren't working, make sure you right click on the folder and see if the tsvn operations come up in the menu. There may be some reason that the overlays aren't working that's unrelated to the working copies.