greetings

i recently bought winfast a7600gt and the performance is really good.the only problem i got is dat the gc cannot be overclocked using the supplied tool,winfox 2.0.the advanced settings for oc is disabled,and ive tried many things (format,update driver) but i still cant oc.ive read in the web that it can be oc.ive changed my psu for that purpose but still remains the same.ive return to the seller and checked for it but they say its ok.

can anybody help me?

how do i unlock then