Have you not got the original disc that came with the printer ?
Otherwise you will have download the software from canon
http://www.canon.co.uk/Support/Consumer_Products/products/Fax__Multifunctionals/InkJet/PIXMA_MX_seri...Took about 30 sec to find it using a search engine (Bing)
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EOS 1D Mark IV, EOS 50D, EOS 30D
EF 24-70 f/2.8 L, EF 24-105 f/4 L IS, EF 70-200 f/2.8 L IS, EF 100-400mm f/4.5-5.6L IS
EF-S 18-55mm f/3.5-5.6 EF 1.4 II Extender
580EX MKII, 430EX MKII
