Why is my modem connection slow – Sony VGN-Z790D User Manual

VGN-Z790DND, VGN-Z790DDB, VGN-Z790DBB, VGN-Z790DEB, VGN-Z790DLB, VGN-Z799DJB, VGN-Z790DHB, VGN-Z790DKR, VGN-Z790YAB, VGN-Z799DHB, VGN-Z790Y, VGN-Z790DKX, VGN-Z790DFB, VGN-Z790DMR, VGN-Z790DAB, VGN-Z750D, VGN-Z790DCB, VGN-Z780D, VGN-Z799DGB, VGN-Z790JAB, VGN-Z790J, VGN-Z720Y, VGN-Z799DIB, VGN-Z790DGB, VGN-Z790, VGN-Z790DLR, VGN-Z790DJB, VGN-Z790DIB, VGN-Z790DLD, VGN-Z790DKB, VGN-Z720D, VGN-Z790DLX