I am Makarand P from the Dell Social Media and Communities team,
With regards to your issue, there could either a malware problem or a registry entry which is corrupted due to which the explorer.exe stops working. To eliminate the problem of malware, you could try a freeware called malware bytes- anti malware. Also you could try using the windows cd to repair your computer. "Repair your computer" option can be accessed by pressing the F8 option at start up. Ensure to insert the windows cd and then run the repair option.
Kindly revert for further clarifications,
Thanks and regards,
Dell Social Media and Communities Responder.