I have two suggestions. They both use the same method, but it depends on how your data is.
If when the form is opened the textbox already has the date in it, you can use the Form_Load event. In this event, set the MinDate property of the DateTimePicker to the date in the textbox...
Me.DateTimePicker1.MinDate = Convert.ToDateTime(Me.TextBox1.Text)
If the date is something entered by the user into the textbox, you could use the TextBox_Leave event or other event that meets your needs to do the same basic thing.
These methods allow the users to still scroll through the DateTimePicker, but they cannot select any date prior to the MinDate property.
=======================================
People think it must be fun to be a super genius, but they don't realize how hard it is to put up with all the idiots in the world. (Calvin from Calvin And Hobbs)
Robert L. Johnson III
CCNA, CCDA, MCSA, CNA, Net+, A+, CHDP
VB/Access Programmer