Information before i get started.

Make of Computer Ect.

Compaq 5070
Upgraded 4Gb HD to 40Gb Maxtor Plus 8
280Mb of ram ( i have access to make it 384)
Processor Speed 350 mhz
OS: Windows Xp Pro.

Well i installed Xp pro and it was successful. I looked at task manager when i first got it running and it said cpu usage 100%. Im like ok then it said (just doing a little bit of rounding) Commit charge 116k/694k. I think the pc was running a little slow so i opened msconfig and went to services and disabled some of them and let the ones that let my internet still work.
I rebooted my pc is at 100Cpu usage still and commit charge at like 104k/694k idle. Is is ok to have my pc always at 100 cpu usage when doing stuff i feel like this is a problem. I know i dont have the best proccessor but should i add another stick of ram to make it 300mb+ ( i dont remember the exact #) or downgrade to windows xp.

you're not much over the minimum specs required for XP pro on your processor

Here's What You Need to Use Windows XP Professional
• PC with 300 megahertz or higher processor clock speed recommended; 233 MHz minimum required (single or dual processor system);* Intel Pentium/Celeron family, or AMD K6/Athlon/Duron family, or compatible processor recommended

• 128 megabytes (MB) of RAM or higher recommended (64 MB minimum supported; may limit performance and some features)

• 1.5 gigabytes (GB) of available hard disk space*

• Super VGA (800 x 600) or higher-resolution video adapter and monitor

• CD-ROM or DVD drive

• Keyboard and Microsoft Mouse or compatible pointing device

I believe i have all of that that is listed but things like Mozilla Firefox take of like 70% of the cpu when running it says cpu 70 in task manager. anything i can do to make my pc run smoothly.?

those specs are for minimum programmes running what's it like if you stop firefox and use IE?