No all drives are not the same for various reasons apart from physical size, SATA, IDE interface for example, the best I can suggest would be to remove the drive and measure it and let us know any details that may be written on the drive, as it is older it may be the ATA 100 IDE type.
A less expensive refurbished replacement http://www.discounte...ct_detail&p=487
and a less expensive new replacement http://www.amazon.co...t/dp/B002IJO3P4
From your laptop specs;
The two DDR 200-pin SODIMM memory slots hold two 512MB memory modules, for a maximum of 1GB.
Adding 2 new sticks of the same Ram will improve performance but you will not be blown away by it unfortunately, use the Crucial system scanner tool to find the recommended Ram for your computer http://www.crucial.c...:20100901184937
there is no need to purchase from there just write down the recommendations and then shop around for the best deal.
Your laptop is listed as being shipped with either a 30 or 40GB HDD, what size HDD is yours and how much available free storage space is available at present, let us know this and we can look at both tidying and freeing up space on the HDD which will increase efficiency.