Aladdin (the ESL vendor) recently released a new version of their driver, which supports Windows XP. Depending on what issue of CAESAR II Version 4.30 you have, you may need to acquire this new driver. (Editions of CAESAR II prior to the December build will have the older driver.)

Click here to go the the "Miscellaneous Download" page of this website. Download the HDD32.EXE file, and put it in your \caesar\assidrv directory. Once there, just double click it and follow the prompts.