lost data on harddisk

hello
i have an IDE harddisk and my windows xp system couldn't see half of it. He only saw 130 Gb out of 250. Trying to see the rest of it i chose one at a time the options in Bios: large, LBA, CHS. From starters it was set on Auto. When i reached CHS the partition of 126 which i had on that hard was erased and it appeared as an unpartitioned space. I lost all my data. And i would very much appreciate if someone could help me retrieve all of my data on that partition.
thanks.

I have no idea of what CHS is, but I believe LBA is the default and what you should have selected.

From wikipedia: http://en.wikipedia.org/wiki/Logical_block_addressing

I have no idea what "large" might be...might want to check your owner's manual or click on the BIOS link (should give some idea).

http://en.kioskea.net/contents/pc/ide-ata.php3 See comments re LBA at ATA-6 section.

Louis

Prior to SP1 there was a limit of 137MB of HDD space that would be recognized, with SP1 a 48-bit LBA was introduced which solved this problem.

thanks
it seemed that it was the sp1 afterall.
thank you for the answers.