Grab AIDA64: http://www.aida64.com/downloads
In the Motherboard section, choose ACPI. There should be a table called SLIC. Make sure it's SLIC version 2.1. If it is, then the BIOS can activate Windows 7 OEM discs. Get a disc from your manufacturer and when you reinstall Windows from that disc, it should just activate with the certificate on the disc.
That said, if it doesn't have a sticker, it's not technically licensed (the sticker is the certificate of authenticity proof), and I'd consider returning it regardless.