Unable to Download anyfile!!!!!!!!!

HI,

I bought my DELL XCD35 in Jan 2012.Since then i could only download apps but couldnt download mp3s,pdfs,mpegs,3gps.I have tried infinite number of times but every time i get an error ("unable to download please retry later"- something of this sort),even though i have a good internet card.It makes me frustated because i am unable to use my internet DATA .

Please suggest a solution (a driver or something)

Thanks in Advacne,

Sunny