Class Installer Denies The Request To Install Or Upgrade This Device Error

Can somebody please tell how to get round this anoying message i get everytme i try to reinstall my epsom scanner, it worked fine when i was on xp pro ,but since i reformmated my computer to which i am now using xp home i keep getting this error,
i have got the latest epsom drivers from them although windows does not recognise the signature

Have you uninstalled the drivers before reinstalling?

Do you have SP2?

This error usually relates to drivers incompatible with the Operating System.

thank you or replying and sorry you havent heard from me sooner but i went to bed having been up half the night trying to solvre this (still have no idea)
I have uninstalled the drives lots of times, the manual says install the drivers first, so i unzip the twain driver from te file i downloaded from epsom but it sends it to its own destination file it wont let me put it where i want to put it. ie on my desktop.,this is the same drivers i used which worked fine on xp pro, its only since put home on the problem started.