"Prove IT 2000" logos, with the sub heading, "make sure your PC has a future," will be slapped on PCs that pass Comet's millennium-ready test.
The retailer will launch the scheme on Tuesday at its store in Croydon.
Retail rival Tiny Computers has also considered the logo sticker approach to advertising the millennium-ready status of its machines. But according to Tiny marketing manager Alison Koster, the company was "unconvinced that stickers on screens make a difference. We state in our literature that our machines are 2000-compliant. It is an issue and there are customer fears."