unknow file with 5gigs on the windows 7 pc

I was trying to reduce some disk space on on my exteal hard drive and I found a New folder with a file in it. the file was with the name "store" and no extension. The size of the file is 5.24 GB.

Does anyone know what could it be and is it safe to delete it, as I have plenty of data on the Exteal hard drive about 1TB which I cannot lose. I do have an AV with firewall as well. Please have a look at the screenshot: