Formulas require Pipe instead of Comma??

Hi Everyone! I have been having an issue when entering formulas for quite some time and cannot figure out how to fix this so thought I would post here and see if anyone else has had this problem and knows the resolution.

Prior to upgrading to Excel 2010 I was using Excel 2007. I received a file that had been modified in Excel 2010 via email...I opened this file and made some modifications to the formulas and noticed that all of the formulas in that file used a pipe instead of a comma. Now all files I have created, modified, saved, etc...ever since in Excel 2007 (and now Excel 2010 since I upgraded) require a pipe. If I try to use a comma I get the message saying the formula I typed contains an error. The formula hints even appear with a pipe instead of a comma. I also recently noticed that when I enter a formula in Access it behaves the same way (requires a pipe), which in turn causes problems in Access.

I would like to change this back so I can once again use commas in my formulas instead of the pipe character.

Example:

normal formula =IF(A1>A2,"Yes","No")
my Excel formula =IF(A1>A2|"Yes"|"No")

I hope someone can help....this is really very annoying since I have used the comma for many many many years, and it is MUCH easier to type than the | character (since it requires a SHIFT and a pinky stretch ). Thank you in advance for any advice!!

I do have XP so my settings do look just a little bit different but....your suggestion made me decide to poke around and I found it!! YOU ARE MY HERO!!!!

I am still confused how this got changed, but happy it is fixed now. The steps I took in XP are....

Control Panel>Regional and Language Options>Clicked "Customize" on the Regional Options tab>changed the "List Separator" from a pipe to a comma.

Thank you thank you thank you!!!!!

Thanks Ron for the info !