Windows customizes your PC to suit different national conventions, such as the formatting of dates and currency values. You could use Settings...Control Panel...Regional and Language Options to adjust these settings.
In some places commas are used instead of a period or point to separate the fractional part of decimal numbers. Since 2004, ViewHAR, ViewSOL and the Charter try to follow the conventions set in your Windows environment (unless you over-ride them). More details may be found in the ViewHAR online help topic "Decimal point or Decimal comma".
A bug or anomaly in Windows 7 may interfere with this behaviour. It seems that Windows 7 may fail to correctly inform programs whether period or comma should be used as the decimal mark. The symptom is that some GEMPACK programs use the Decimal point even though the Windows system is set to use Decimal comma.
Fortunately there is a very simple fix. Suppose Windows 7 is configured to use Finnish conventions (including decimal comma), but ViewHAR is (wrongly) using decimal point.
and the problem will be permanently fixed (just changing to something else, then back to your desired setting, reminds Windows 7 how it should behave).