upgrade path for old laptops

Edited excerpts from my reply to some queries about upgrades for old laptops - 

 So as I understand, your two questions are:

1. Can the hardware upgrade (to SSD + more RAM) be avoided by reinstalling the OS / drivers

2. Can the SSDs be installed along with the HDDs.

1. Reinstalling the OS will definitely speed up the machines. But with 4 GB RAM, judicious use would be needed to avoid the machines "going slow". The following can help - 

(a) use Linux instead of Windows - here is a comparison for a fresh installation on an old Lenovo laptop in my room - 

Time taken for Windows 7 to boot, open firefox and open youtube.com - 3:30 minutes.

Time taken for Linux to boot, open firefox and open youtube.com - 1:15 minutes.

Similarly, Windows takes 40 seconds to shut down, while Linux shuts down in less than ten seconds.

(b) open only a couple of browser tabs or windows, and not too many of them 

(c) open only one application at a time, and be prepared to wait for 30 seconds or so for things like MS Word to load.

Reinstalling the OS would almost certainly help to some extent, but to avoid the limitations above, adding RAM and switching over to SSD would be needed. Windows 10 also has something called "Fast startup", which would make boot up times faster than with Win8. Maybe boot times can go from 3 minutes to 2 minutes with an OS reinstall. But it would certainly become much much faster with an SSD and with 8 GB of RAM - most probably it would boot in 45-60 seconds and open apps like Word in under 10 seconds. 

Replacing RAM alone can avoid "slow" behaviour once the machine has finished booting and loading the required apps. Booting up would still be slow. RAM could possibly be scrounged from one laptop and put into another, but this would need the RAM which is already installed to be a single 4GB stick. Those laptops have 2 slots. So, if you want to put in 8 GB, you would need 2 sticks of 4 GB each. You can't do that if your existing laptop RAM consists of two 2 GB sticks.

So, in summary, if you want the laptops to become optimally fast, you would need to spend the quoted amount and do an OS reinstall. If you wish, you could ask the tech to do the upgrade on one piece and see the results for yourself, and then decide if it would be worthwhile to do for the other laptops. 

2. In order to install the SSD along with the HDD (as against instead of the HDD), the laptop must have two hard disk bays. Usually the old laptops don't. Or you can remove the DVD drive and put the SSD in that space instead. But for that, you would need a caddy or holder which would cost around Rs. 250 - https://www.amazon.in/Digital-Device-2nd-Enclosures-Compatible/dp/B09MFNK4PG/