You can either turn off the Virtuemart logo in the Configuration > Site > Show Footer checkbox, or you could go into the code (offhand I don't know where it is) to change the text, or if you want to change the logo then you could check in the Components > com_virtuemart > shop_image > ps_image > powered-by-virtuemart.png and change the image with another image with the same filename and filetype (.png)

Now see how easy it is to give people some information? How about it, development team?

Hello Eugen, I bought a hosting package with ecommerce joomla 1.5 .. I would like to buy the new template ecommerce advertised on your site .. and 'can get assistance configuring it? so you have a website where I just have to ready to upload and manage my products .. thanks Roberto