[Help!!]error converting data type nvarchar to datetime

hello everyone, iam not familiar with sql or .net, so iam looking for someones expertise!
Iam using Microsoft dynamics POS 2009 on windows 7.
along with the point of sale package comes SQL Server 2008 & Visual Studio 2005.
when trying to generate a sales report i get this error;

"Unable to retrieve report data for the report.

Error Details: Error converting data type nvarchar to datetime."

It was working before i reinstalled windows 7 (up from win 7 Prem to Ultimate) i also done windows updates which included updates for the SQL server package.

i had a search around to see if i could find answers but its all a bit over my head, walk through instructions would be a help.

if anyone would like to give a helping hand, that would be amazing!

thanks, Chris.

Best guess is your default date format is screwed up from what it was.

Is this a custom report you wrote, or one you are using/modifying?

You can do this at the beginning of your sql:

Set dateformat 'dd/MM/yyyy' or which ever way around you have it.

Oh and watch for capitalisation - m is minute and M is Month. Or is it the other way around...? You get the point...

PS - this is why it is a really BAD idea to store dates as anything other than datetime.