XP Insane slowdowns - Any ideas?

[pyrre]

I have run my XP install for a little over two years now. I have never defragged my disks. I use NTFS and have never really seen any difference in defragged or not... even when my disks are full.
However. installing and removing programs build up much unwanted entry's in the register file. so an occasional cleanup is needed.
I use symantec antivirus, spybot and firefox...
And i never really experience any significant performance loss. And if the system gets slow, i do a reg cleanup...(manually)...
My pc system is:
Intel P4 3200 HT
Asus P4P800
2gig ram
XFX 6800 ultra
Onboard audio and network
Promise IDE controller
and a total of 1TB disk space...

[pyrre]

What do you use to clean up your registry?

regedit

I manually remove any unwanted input...

EDIT:
And of course, spybot with teatimer.

But for the last two years i have never really experienced any significant performance loss...
After i became aware of what i install. Especially components from internet... blocksite is a very nice firefox addon...

[pyrre]

@ Hodgkinson

Well...
Using firefox with adblock, blocksite, flashblock, stop autoplay and java console (e new version of java console is needed for firefox 3.0), Spybot with teatimer (even though it wont help firefox much. But it will stop any spyware from using iexplorer.exe...) and of course symantec corporate antivirus.

Doing this you never really see anything to spyware/maleware. unless you accept downloading some *.exe codecs to see porn vids on the net. :-D
As for internet connectivity.

However, using win xp. you should never have less than 1gig ram. I have 2 gigs. and i think it is not enough...
I have never defragged any disk after i started using NTFS..
And i frankly don't see the point... 1 maybe 2% performance increase on modern computers...

And manually cleaning the registry. it really is no fuss... be aware of what you install, and when uninstalling it. remove it from registry... not really a problem...

My previous windows install was two years old. and it was originally installed on a AMD system. but was later changed to intel. I manually removed the AMD drivers and it worked flawless... only reason for reinstalling windows... well.. porn and spyware.... bluscreen on every bootup... :-(