When you try to install Windows XP on new Acer Aspire 4520, you'll find error message like this :-
"Setup did not find any hard disk drives installed in your computer"
Basically, if you are installing Windows XP on Acer Aspire 4520 you just need to configure SATA mode in f2 options from AHCI mode to IDE mode. But, if you are installing Windows Vista, you should ensure that the SATA mode is in right selection ; AHCI mode. This is because, Windows XP can't be read in AHCI mode. We should thanx to Acer because they flashed the bios so we can choose to install Windows XP or Windows Vista without installing particular SATA AHCI driver before beginning to install Windows XP. So, here we goes. 1. Turn on aspire 4520
2. Press F2 to enter bios, -> "Main" -> select "SATA mode"