According to Google, Windows XP expired in 2014.  You might be able to use 2015 or 2016 but I can't guarantee it.  I'm getting messages from 2021 that I may not be able to use future updates on Windows 7 in the near future.

I don't know where you will get a legal, working copy of a version that old now.  Sage doesn't sell them anymore.

What is wrong with your 2008 version?  I don't think there are many must-have features in 2015 that 2008 doesn't have (only one comes to mind - bank rec reports can be sent to pdf but not in 2008 and there are ways around that if necessary).

Thanks. I think you make sense to just stick with older version I have. The main thing I've run into is that I have three years worth of data entry I could do...went with a different system, you could say manual for the simple fact I needed to get stuff caught up quickly and summarizing was faster than a whole bunch of data entry. I'll likely do the same for this year. Now, I want to revisit using the software but do I just setup a new file and thus bunch of new recurring entries and updating all my clients etc? Do I just take same file I was using and just skip it forward two years or three for that matter if I decide not to input all of this year's stuff? What about reconciling bank accounts? I'd have to create entries to ensure my bank starting balances match for start of 2021. If 2015 version is not much different of beneficial than 2008 then you are right makes no sense to upgrade. It's either go with latest version, even 2020 and buy it starting fresh or go with tried and true older version not reliant on updates for anything even internet. It is manageable regardless.

To be clear, I was not specifically suggesting you stay with the old version.  I asked what was wrong with it.  The answer I am getting is "nothing but I haven't done my bookkeeping in a few years and I am wondering if I should upgrade before I start doing it again".  I may be paraphrasing here but your requirement to be working with XP indicates you should stay on the older version and just get your bookkeeping caught up.

There are several ways to handle all the problems you have but I can't tell you which is best because I have never had to deal with this type of work where I have not done all the bookkeeping to catch up and then file the taxes.

One approach may be the following:

You have year end numbers for several years.  Taking your current file that has account balances as of let's say sometime in 2017.  You have the year end numbers you calculated for 2017.  Post the differences to make your balances at year end match.

Then post the differences to catch up to 2018, 2019 and then decide if you want to do your bookkeeping for 2020.

As for bank recs, I hope you haven't had any fraud going on because it sounds like you haven't done one in a few years.  You might do a manual bank rec for the final period you need to catch up on, then make sure you post any outstanding entry as an individual entry.  Then turn off and turn on your bank rec (after taking an appropriate back up of course) and start over going forward, if you are planning on keeping up with your bookkeeping.

This approach may or may not be the best.  Something tells me that if you did several year ends calculating manually, then you don't really have a lot of data entry (several hundred entries in year, not thousands).  It would be just as fast to do the bookkeeping properly in my opinion.

I am sorry if this sounds harsh or not helpful but you have got yourself into a mess and the best way to get out of it is to put in the work to get it done and then keep on doing the work so you don't get behind again.  Retroactive bookkeeping usually costs people more money than proactive bookkeeping but it depends on how long you leave it.

Thanks, no offence taken. There is a personal reason for dropping things and a few attempts to hire help did not pan out. Regardless, we are talking about 2500-3000 entries a year. Specifically related to billings for rentals and receipts from tenants and the like. It is quite a bit of data entry. Tallying up numbers manually is not bad nor going through bank stmts ensuring transactions going in and out make sense. It's a catch 22 at present but you have given me some great feedback and I appreciate this. I've also got the option of working with rental property specific software but cost vs benefit is a consideration. I find it easy working with Simply. Again, thank you. I am looking at the manual entries for bank recs like you say to capture a specific period and turn the feature on and off as you say. I've got to work through that by creating a dumby file of sorts and see how it works. Inputting all of this year's details will take a bit of time and effort but doable. Again, due to personal health reasons within my family it basically meant dropping everything and leaving to take care of this for months on end and continued back and forth trips etc. Regardless you have helped with my decision making process.