ram.please

I have loved playing HL1 several times, but now that I have sold my desktop can I play the same on my laptop? It's config is Compaq Presario,1.3 Ghz, 256 Ram.Please suggest.

I have an old Compaq Presario Desktop PC with Abit BD-70G & Intel 845G with 128 MB DDR SDRAM working at 266MHz.I want to buy a new a 512MB RAM.Which type of RAM should i buy so that it doesn't conflict with my existing RAM.Please give me some details about the best DVD Writer that is available...

i have a old Compaq Presario Desktop PC with Abit BD-70g motherboard & 128MB DDR SDRAM working at 266MHz.I want to upgrade my RAM.Please tell me which type of RAM will be suitable for my PC.I want a RAM that will work with my existing 128 MB RAM.

I have a Compaq Presario with Intel 845G with Abit BD-70G motherboard with 128MB DDR SDRAM working at 266 MHz.I want to buy a new 512MB RAM.Please tell me the specification of the RAM that will work on my system.