OK, I would them recommend to ZIP the contents of that entire ../data folder just to have as a backup.
Then uninstall PostgreSQL 8.3 using the Start > Settings > Control Panel > Add or Remove Programs window.
Then go to the Start menu and select Run. Type COMMAND and hit enter and this will open a DOS window.
Type the following:
net user postgres /delete
and hit ENTER. Then type EXIT to close the DOS window.
Then reinstall PostgreSQL again. When you get to the window that has the "Initialize Database Cluster" at the top left corner of the window UNCHECK that box and click Next. This will force it to try to reuse the ../data folder that should remain even after you uninstall PostgreSQL.
Then restart the computer and try running PT again when it comes back up.
