Thanks very much Peter for your information. With no doubt there are several software for analysing TCSPC data, but I faced a problem with importing files in txt format, and I was not able to convert them into a compatible format. Cheers.
In the very beginning I tried FAST software, which is according to my information uses some computational algorithms which are very powerful in solving non-linear least squares (which is usually the case in fluorescence decay kinetics) and giving reliable results. I tried to import my files ( they are just like you described above) but it did not accept those files. In the case of fluofit I installed the software and when I try to run it there is an error message which is "Error 7 Hardlock not found". I hope that clarified the issue to you.Regards.
The input data format of FAST are typically text files or ASCII format. I use the software regular and had no problems with that, which software version of FAST do you use or is it possible for you to convert it to ASCII for instance with ORIGIN ?