What are the things you need to be aware about before buying an Solid State Drive SSD?

never wear out , faster operation, no disc problems , has more gbs than a disc for the same GBs--- 125gb sshd=250gb disc

Of course. All PC's have DRAM.
If you want to increase DRAM you can purchase from:
Crucial com DRAM solid state drive SSD memory upgrades for Dell Mac Apple...
they also have a tools to check your system ram size.
Crucial com DRAM solid state drive SSD memory upgrades for Dell Mac Apple...

You could buy a "sled", an external hard drive enclosure for 2.5" drives and connect it to a running computer via USB to save your data. This assumes that there is no encryption on the drive that you may have used.

It does sound like there's a major problem with the Solid State Drive. When you boot the system, press F1 or F2 (or what is shown) to get into the setup. When in, do you see the drive in question showing on any of the screens?
You may need to open the system up and reseat the SSD.
If reseating it doesn't help, you may be eligible for a replacement SSD from it's manufacturer. Many Solid State devices have a lifetime warranty.

I hope this helps. Post a reply if it doesn't or if you need further help.

The best way to speed up W7 is to install an SSD (Solid State Drive), such as one of these drives:
http://www.compusa.com/applications/category/category_tlc.asp?CatId=5298&name=Internal-Solid-State-Hard-Drives&

While they are expensive, you will_not_ regret the investment. To save $, you don't need to purchase a large SSD drive. Put W7 on a small capacity SSD (commonly referred too as a boot drive) and then use a regular hard drive (your old one) for mass storage. For example, on my computer, I use a 40GB SSD for W7 (C:) and a regular 500GB hard drive (D:) for music, videos, large downloads, pics, etc.

There are also a plethora of websites that will show you how to speed up W7. Here is one:
http://www.computingunleashed.com/speed-up-windows-7-ultimate-guide-to.html

Another way to speed up W7 is to install more memory, but you won't get near the noticeable performance increase as an SSD. In fact, after installing an SSD, if you try to enable ready boost on a flash drive W7 will tell you that it is not neccessary because you already have an SSD that is faster.

I found one for £202.00 a 64GB one.. what an obscene amount of money!
http://www.bzsale.com/product/NEW-64GB-SSD-1-8-ZIF-MLC-for-DELL-D420-D430-OQO-umpc_P7896-GBP.html

I'd suggest you invested in a portable hard drive for your data at a tenth the price you could get a 100GB drive