Is it worth the upgrade?

It depends on what is causing the lagging.
If you hard drive is the bottleneck here, an SSD would certainly be a worthwhile upgrade.
Even if the hard drive isn't the problem, an SSD can noticeably cut down on startup and loading times.

8GB RAM would need a 64-bit Operating system to be utilised, since 32-bit can only address something like 3.3GB. So a RAM upgrade would only be useful if you can change/upgrade your OS to a 64-bit one.

Whether the 8GB ram would help your computer - that depends on what you use this machine for. If it's the processor slowing the computer, the extra RAM won't do much to stop it.

Hello wjonesy;

With a 32bit version of Win7 the RAM upgrade would be wasted on your laptop.
And even with a 64bit version and 8GB RAM you'd not be able to notice any performance improvement.

A SSD would only affect storage access times. It would give you faster boot-up, and faster program load times. But overall, it wouldn't make you laptop noticeably faster and probably would not fix the lagging your mention.

Have you done a 'clean' install of your OS lately?

I dont have the disc for my OS so cant do a 'clean' install, or can I??

I am going to change to 64 bit and do a full install of windows 7.

Dont think I will go for 8GB RAM

You should be able to do a clean install using the hidden recovery partition on the hdd.

Did your laptop ship with Vista?
If so, you probably want to hold off on doing that clean install till you figure out what you need to do.

Yes it shipped with vista. I dont know whats causing the slowness. Also windows explorer crashes and restarts at least twice a day. So many reasons why that happens I dont know what to do about it.