Sony Vaio VGN-CR343N Laptop  

Oh!! Well, your configuration is decent and I am sure its not the hardware that's causing these absurd problems.
Speed of processing decreases either when you run many programs on start up, or if the system is infected.
But then you have a problem with battery as well.
You should write this to Sony customer care. Find the Email ID on their website.
And, its under warranty, try getting it replaced.

if you are running Vista then you will probably need more than 1gb of RAM, that is the minimum RAM recommended for vista, but i would recommend at least 1.5gb, my desktop has 8gb and it still slows up sometimes. the processor is perfectly adequate and i doubt that is the problem. have you checked for viruses? i like to use a program called CCleaner to clean up unused data which clogs up your hard drive and memory, it also 'fixes' registry issues.

i'm sure if you search through eBay you will be able to find a replacement battery that could last 5 or 6 hours and sony would probably replace the CD drive if it is faulty and under warantee.

you should consider which os you hhave on your laptop so if you have a 64 bit windows os surely your configuration is not so powerful considering a core 2 a cpu and just 1 gb of ram...normally you should have a little bit more!!In reality when you buy a new laptop as regards speed and perfromances you should always upgrade ram and cpu when it is possible because almost all producers they give you a base configuration in this way the final or startin gprice should result really ok but perfromances in some cases can be not as good as you imagined!!