Generating random numbers with normal distribution in Excel
Rand() does generate a uniform distribution of random numbers between 0 and 1, but the norminv (or norm.inv) function is taking the uniform distributed Rand() as an input to generate the normally distributed sample set.
IF you have excel 2007, you can use
=NORMSINV(RAND())*SD+MEAN
Because there was a big change in 2010 about excel's function
Use the NORMINV function together with RAND():
=NORMINV(RAND(),10,7)
To keep your set of random values from changing, select all the values, copy them, and then paste (special) the values back into the same range.
Sample output (column A), 500 numbers generated with this formula:
As @osknows said in a comment above (rather than an answer which is why I am adding this), the Analysis Pack includes Random Number Generation functions (e.g. NORM.DIST, NORM.INV) to generate a set of numbers. A good summary link is at http://www.bettersolutions.com/excel/EUN147/YI231420881.htm.