If your table name or column names includes white space, you need to use them with square brackets like [Asset Status]. But this is not recommended. Would be better changing your column name to something else if you can.
Read: Database, Table and Column Naming Conventions?
Also use using statement to dispose your database connections and objects.
using(SqlCeCommand cmd = Login.sqlConn.CreateCommand())
{
   cmd.CommandText = "INSERT INTO tbl_AStatus ([Asset Status],Remarks) VALUES (@a, @b)";
   cmd.Parameters.Add("@a", SqlDbType.NVarChar).Value = txtAssetStatus.Text;
   cmd.Parameters.Add("@b", SqlDbType.NVarChar).Value = txtRemarks.Text;
   // I assume your column types are NVarChar
   Login.sqlConn.Open();
   int a = cmd.ExecuteNonQuery();
   MessageBox.Show(a.ToString());
}
And don't use AddWithValue method. It may generate unexpected results sometimes. Use SqlParameterCollection.Add method and it's overloads.
Read: Can we stop using AddWithValue() already?