Is it possible to download Hd loader or hd advance install it on a hard drive thats setup as a slave and then plug it into the ps2?
NO. To be a slave HDD recognised by windows it needs to be formatted in FAT32 or NTFS. So you could add any ISO file you like to it but all would be useless in your PS2. The software you speak of will format your PS2 HDD into the PS2 recognisable format (HDA or HDL one or the other)when the HDD is installed in your PS2 and the software is booted. You could format the slave HDD in your PC using WINHIIP and add game ISO's with this program aswell, but you still need a method of Booting your burnt image of HDA or HDL on the PS2. You could boot it with Swap Magic. Remember if its not a pressed disc, it will need booting somehow.
