Decimal Spaces

You can increase the number of digits after the decimal place in SME to up to 4 digits by going to Setup module > Company > Systems. Locate the Number of digits after the decimal for currency field and enter the number.

If the currency decimals don't change in SME, you need to change your settings in Windows.
1) In WIndows, open the Control Panel
2) Double click on Regional and Language Options
3) On the format tab, click Customize this format
4) In the customize Regional Options window, click the Currency tab and set the number of decimal spaces in the No. of digits after decimal field.
5) Click Apply and Ok