There is no means to update from SP3.0 to SP3.1, because $ w9 t9 C, v9 U0 A s* Z1 E" a1 S" _
"Please note that the only difference between SolidWorks 2008 SP3.0 and SP3.1 is production support for Microsoft Windows Vista 64-bit, so it is not necessary for customers on other operating systems to download this Service Pack. "