If the cause of the fall of the Conductor, just that its disabled by mistake or as a result of accidental failure in the system, you just need to restart it. To do this, press and hold the CTRL and SHIFT keys, and then press the ESC key. This combination opens the task Manager of the OS. If this doesn't work, use another combination: CTRL + ALT + Delete.
By default, the Manager will open on the "Applications" tab in the lower right corner where you placed the button labeled "New task". You need to click the mouse to open the window "Create new task".
In the input box type explorer and click OK. In this way, you will restore the work Explorer Windows.
If you run this app does not happen, then there are two possible reasons. The first is that the result of the failure of the conductor is not switched off, and "stuck", i.e. does not react on incoming commands. In this case "this" instance of the program it is necessary to force quit. To this end, the task Manager window click the Processes tab, under image Name, locate the title explorer, select it and click "End process". After that repeat the two previous steps.
The other reason is more serious – it was probably deleted or damaged executable file explorer.exe. In this case you need to find the same and place it on the same place (in the WINDOWS folder). You can try to find it on the disk with the operating system distribution and can be found on the Internet. The main difficulty will be that you will not be able to use the OS to copy the file to the desired folder. So, in addition to the file itself, you need to find the net and record a boot floppy (or CD/DVD), with any file Manager, you can add the same media file Explorer, boot from a floppy and using file Manager to copy explorer.exe to the desired folder.