well u neither u mettion the OS nor the kaspersky product name or the version... well i am counting that OS is winxp & product is Kaspersky AntiVirus Personal Pro 5.0...
u may try to back up this folder content...
x:\Documents and Settings\All Users\Application Data\Kaspersky Anti-Virus Personal Pro\5.0\Bases
then after the reinstall just replace the folder...
but best would be an offline but full update... ckeck this... u dont need an active internet connection for it... download the zip archive from any where then bring it to ur PC... & configure KAV to update from local hard drive...
