What is the way to change size in a cell in dataGridView to 8.25
This does not seem to work.

dataGridView1->Rows[b]->Cells[10]->Style->Font->Size = Font->Size(8.25F);

You can get a Fontsize property you can not set it.
If you want to set it make a new font instead.

Okay, Thank you, I am not sure how to set something like this.

For this scenario, what is the method to achieve this and do I set both the font and size at the same time then ?

Use something like:
C->Font = gcnew System::Drawing::Font(C->Font->Name, mySize, C->Font->Style

ddanbe.. thanks..

This did it:

dataGridView1->Rows[1]->Cells[10]->Style->Font = gcnew System::Drawing::Font(L"Arial", 8.25F, System::Drawing::FontStyle::Regular, System::Drawing::GraphicsUnit::Point);