richy4 , for most players bought off ebay, especially the 4GB/8GB varieties, usually most are hacked.
If they are, formatting via Windows would not be able to remove the hack.
I'll suggest formatting with MP3 Utilities Disk Tools, guide here
http://www.mympxplayer.org/how-to-re...ck-vt2400.html
Formatting would not remove the firmware. Unless you have copied more than the actual capacity of the chip. Causing a firmware corruption due to overwriting.