Several points:
- You do *not* need to upgrade. You can continue to run Windows 7. Although support for Windows 7 is ending, that does not mean you have to upgrade. It means that Microsoft will no longer provide updates to it. But you can continue to run Windows 7, if you want to; just be sure you run third-party security software that is kept up to date.
- Your hardware sounds basically OK for Windows 10, but it's possible that some of it may not be compatible with it.
- You may need Windows 10 drivers for some of your hardware and they may not be available. Check on the computer manufacturer's web site.
- Regarding performance, I'm not so sure that you need to upgrade the hardware. Yes, the local computer shop recommended that you do, but that's probably mostly because they want to sell it to you. The poor performance you are experiencing can be for many reasons, for example, malware infection, the background programs you have running etc.
- You should check how much of your RAM is in use when you run Paint Shop Pro. Unless most of it is, you probably don't need more RAM.
Are you running 32-bit Windows 7 or 64-bit? If the computer's motherboard/CPU 32-bit or 64-bit? Unless you're running 64-bit Windows, you aren't using more than about 3.2GB of your 6GB of RAM.
- Word 2007 should run under Windows 10. Most programs that run under Windows 10 will also run under Windows 10; the main exceptions are some utilities and some games.
- Buying a new computer does not get you a new version of Word. Whether you stay with Windows 7 or go to 10, if you want a new version of Word, you have to buy or lease it. The same with all other software you run.
So what should you do? I recommend that you first check how much of your RAM is in use when you run Paint Shop Pro. If that's not a lot, you should explore in depth why the computer is slow. If you are happy with Windows 7, stay with it.
If however, you do want to got to Windows 10 (remember, you don't have to), look into your hardware's compatibility with Windows 10 and Windows 10 drivers being available. If neither is a problem, you can upgrade. But you can also buy a new computer.
Which should you do, upgrade hardware or buy a new computer? Unless any needed hardware upgrades are very minor and inexpensive, it's almost always a better choice to buy a new computer. With a 9-year-old computer, you can expect to have components die and need to be replaced fairly soon. Upgrading may seem like the cheaper choice now, but it may turn out not to be.
So my final recommendation: either stay with Windows 7 and address the slow performance issue or buy a new Windows 10 computer. Your choice. Do not do substantial upgrades.