Can Putty be used to send serial data from the PC to the PIC? How?
PuTTY works well as a general terminal emulator but for work with embedded systems I prefer Realterm which has a lot of support for working with binary / hex. When sending a file you get the option to set a delay between each character, each line and can send the same file multiple times with a delay between each time:



So using that you could either add delays or implement flow control (which is set on a different tab). Another alternative to using flow control is to implement one of the fairly ancient protocols like XMODEM which are fairly simple and don't consume a lot of code space, if you have a little over 1k of RAM available then I've used this code and it works. ExtraPuTTY is a fork of PuTTY that adds XMODEM and a few other file transfer protocols.