Don't canon themselves provide any? - http://www.canon.co.uk/Support/Consumer_Products/products/scanners/LiDE_series/CanoScan_LiDE_70.aspx Normally, drivers and the like come from the device manufacturer. ( the above was for W7 ( assume 32bit as they also have a specific W7 64bit listed ).
If thats no good, then see the FAQ tab, specifically - "To use the product you are using in the Windows 7 environment" question.
If still no joy, ask canon - http://www.canon.co.uk/Support/Consumer_Products/contact_support/Index.aspx