Add Environment.NewLine after each body line.
A better way would be to do this:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSend.Click
Dim strSubject As String 'subject title
Dim strBody As String 'Body of message
strSubject = "Need Remote Pc Help" 'store subject in variable
'store body in variable
strBody = "Here is All the Information that you will need:" & Environment.NewLine
strBody &= txtName.Text & Environment.NewLine
strBody &= txtAddress.Text & Environment.NewLine
strBody &= txtPhone.Text & Environment.NewLine
strBody &= txtProblem.Text & Environment.NewLine
strBody &= txtIP.Text
Dim mail As New System.Text.StringBuilder
strSubject = "?subject=" & strSubject
mail.Append("mailto:backstback@hotmail.com") 'email address
mail.Append(strSubject) 'subject
mail.Append(strBody) 'body of message
SendMail(mail.ToString)
End Sub