Resistor Finder is a Freeware program for Windows 95/98/NT from Bertrand Zauhar, VE2ZAZ. It allows the electronics designer or hobbyist to find a combination of 2 resistors that, when connected in parallel, will provide the best match to a desired resistance.
I installed it on my old Win98 machine but was disapointed to find that it did not tell me where to find the resistors just which resistors I needed. Turned out I needed one from 3 draws across and two down and another from five across and four down. Room for improvement then.
I haven’t tested it under Windows 7.
Bertrand’s website is in English and French and you can find more interesting projects and programs there.