Questions about external drives for XP

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I am a "young" senior citizen and an avid enthusiast of digital photography
and editing. Due to the large size of Photoshop files and that I cannot
afford a new PC with a faster processor I am looking for ways to make my PC
more productive. It's been slowing down quite a bit lately. I have IntelP4
and have upgraded to 2GB of memory, so don't think memory is an issue. I
have a 80GB HD with 48GB of free space. I move important picture and project
folders to DVDs for safety but also to keep more free space on the hard
drive.I also keep my system maintained very well (clean, defrag, A-virus,
firewall, etc..,) it'd help me to know the following:

- What changes can I make to empower my PC to "get back to speed"?
- Have been thinking of getting an external HD, is that a way to help? And
when an external HD is connected to PC and turned on, is it taking
"energy"?? from the PC's performance?
- Is it OK to move My Picture folder to an externa HD and use it from there?

Thanks for any suggestions and/or ideas you can provide. Joan


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