I would suggest if your going to continue to run with only 1GB of ram you look into your start-up eateries and disable any unneeded entries, this way it will leave you with plenty of free ram space leaving your computer to run faster and smother with more labour intensive program's
I resonantly did this with a friends P4 1.33GHz pc with only 1GB ram and improverd the startup time from 5mins down to just 2mins and 35 seconds, general performance also increased
i did also give the system a good clean up too
i will list the things i did and installed.......
1: installed Tweak UAC and enabled quiet mode Disable annoying Vista UAC popups with TweakUAC (FREE)
(stops constant security pop-ups)
2: removed any bloat-ware and unused programs (You may want to scour your C:// drive for leftover files and folders from any un-installed software)
3: installed Spybot search and destroy The home of Spybot-S&D!
= (no Scanning done yet) 1st right clicked and changed properties set to run as Admin, then from inside set to "advanced mode", under tools bottom right i selected Start-up entries (i use this as it will give a brief description of what each entry is and if its needed) now i remove any unnecessary startup items I.E Quick time and MSN (windows Live) "BE SURE NOT TO REMOVE YOUR ANTI_VIRUS"
4: install Adaware Ad-Aware by Lavasoft - Antivirus software, free spyware removal, firewall
(just my preference)
5: install Ccleaner CCleaner - Home
Use this to clear any temporary files then run the registry clean-up facility (Make a backup when prompted) "fix all", now run the registry clean up again (there will most likely be more to fix)
6: run the above Spybot (don't forget to immunise) and then run Adaware
7: download and install Auslogics Disk Defrag Disk Defrag - Fast and Safe Defragmenter for Your Disks
(i find this faster and more intense than windows defrag
All being well your system should run a lot faster and smoother