vlookup error

[jms329]

Sometimes when using the vlookup function I get the following error:
Invalid reference. This file version cannot contain formulas that reference
cells beyond a worksheet size of 256 columns (column IW or higher) or 65536
rows.

I'm not really up on computer language, so it's preferred if your reply
could be for the layman.
OS is Windows XP w/SP 3
Excel verision is MS Office 2007

Any assistance is appreciated. Thank you.

 

[Jerry W. Lewis]

Prior to Excel 2007, worksheets were limited to 256 columns and 65536 rows.
If you save as an .xls file (instead of one of the 2007 specific file
formats), it sounds as though these limits still apply for backward
compatibility.

Jerry