To recover PicoLog Recorder, have a look in the taskbar to see if there is a 'PL' icon - double-click it to restore the window. If PicoLog is minimised it will show as an icon in the System Tray, meaning that if you try to run the program, PicoLog Player will appear. Which version do you have installed?
Depending on your version of Windows, the icon should appear in the taskbar like this (you may need to click on the arrow to view all items on the taskbar):
If you cannot find this icon, open Windows Task Manager and look for a task named 'plw32.exe', select it, and click the 'End Process' button.
If your TC-08 is showing in Windows Device Manager, as shown below, but you cannot pick it up in PicoLog, then it may be that you installed the wrong driver.
Please uninstall the software and reinstall it. If you have a USB TC-08 then please select 'TC-08 (USB)' in the drop-down list that appears during the installation process or if you have a serial device, then choose 'TC-08 (Serial)'.