I cant find my serial number where can i locate it on my archos 5

Look at the back of your archos 28 to indicate or the receipt.

Is it archos 5 or archos 5 IT ?
For archos 5 IT is already upgrade to 2.2 as far as I know.
For archos 5 I don't think there is one and with archos they don't bother doing anymore upgrades for older models.

Found this for the archos 5 IT.
http://www.youtube.com/watch?v=GzgfCTp6--k

When you put in the details of your product now, on the web-site, there is the option to transfer registration of a product to you. The product details are key and serial number which can only be obtained by physically having the unit. It's so easy now.

The serial number is written at the back of the device, it should look something like this:

well you can ask archos support to help for archos product key

The Serial Number is written on the back of the device.

Examples:

http://www.archos.com/plug-ins/index_dish.html?country=us&lang=en

remove the battery and read in the sticker of the exposed 2.5´´hard drive.The serial number is indicated with SN or S/N plus several numbers.

serial number or model number - isn't archos 605 is the model number? serial numbers are usually written inside battery compartment or battery cover and rarely displayed via settings/information menu

same problem.

try this one:

KING-RAIL-0FOX-1146