RISKS: Excel garbles microarray experiment data: "For example, the RIKEN identifier "2310009E13" was converted irreversibly to the floating-point number "2.31E 13.""

Although in most cases you can turn off Auto[anything] features and MS products, it has been my experience that you can never be sure that you have got all of them turned off. There should be one option:

[x] Never, ever let Excel automatically modify any data.

Same for Word and PPT.