Tough luck, I guess, as neither Altavista nor Google gives
any results for "AdfsUd.sys"...
(Are you sure you spelled the filename right?)
This should be a lesson for you NOT to buy such stuff from "just some person on the Net": if the device stops working (or doesn't even start working when you get it), you'll have noone to complain at...! Obviously, you got no manual or driver disk or URL of official support page etc. etc...
I'm astonished that people keep falling for these online auctions, only to buy something for a few dollars less than if buying them in a proper shop; or buying some non-brand, cheap junk instead of buying a device from a well-established brand (yes, for a higher price but also of higher value, support and reliability)! (Perhaps, preferably, a "physical" shop you can go to, enter, sort through different brands and models of devices, ask the shopkeeper for his opinion and suggestion, and take your non-functional device back to during the warranty period.) Jesus, people, wake up!
(From the proud and satisfied owner of an
iRiver H140 with 40 Gbytes of mini hard disk and
Rockbox third-party firmware; currently costs about 400 US dollars but discontinued)