DIOODE.. congrats on thinking about buying maxtor .. i did too.. i am suffering as my ZX440 would not detect beyond the 32 GB of the 40 GB HDD.
It will work sureshot.. but it will show you only 32GB if your BIOS is not the latest .. so in that case you will to update the bios.
Now here is most important part.
GET THE HDD AND INSTALL IT. ASK DEALERS FOR ANY OTHER ISSUE YOU MAY BE CONCERNED ABOUT.
THEN SEE IF IT DETECTS FULLY ie 40 GB. IF NOT THEN GO TO THE ASUS WEBSITE AND follow instructions on how to update the BIOS.
IF YOU FAIL TO UPDATE THE BIOS WITH ANYTHING FROM THE WEBSITE ( however i havent seen one case except myself who hasnt been able to ..usually when ppl update either the bios goes bust or it gets updated successfully .. neither happens for me ) THEN YOU HAVE TO LOCATE THE CD ROM THAT CAME WITH THE MOBO. MAKE SURE YOU DO THIS AFTER TRYING and TESTING ALL THE BASIC UPDATE methods. SEARCH FOR BIOS UPDATE THREADS IN THIS FORUM. THEY HELP .. (not me but

)
NOW FROM THE CDROM TRY TO FIND THE UTILITY FOR FLASHING THE BIOS. GOOD LUCK!
PLEASE PLEASE .. IF YOU HAVE the CDROM then CAN U SEND ME THE "UPDATE FILE" AND "FLASH UTILITY" FOR THE P299 440ZX Board. I am living with a MAXTOR 40 GB MINUS 8 GB for 4 MONTHS now .. unable to update the BIOS.
ANYWAY other than this problem there may not be any complications.
Good luck
and remember my request.
Thanks