Slow system, please help!

[#1]

Hello! Wondering whether anyone could suggest how to solve this problem.
I am running XP on my desktop. My computer is painfully slow to load, and to open applications. Once I use the applications, all is running smoothly. This has been going on for several months.
I have:
- not got any viruses, spyware etc.
- defragmented my hard drive.
- not installed anything new.
- ran Ashampoo and got rid of any clutter.
What else have I forgotten?
Thanks for your help!
Blue Rhizome, on the verge of a nervous breakdown.

[#2]

a how much ram have you got?, any other details of your machine?

[#3]

You say you have not got any viruses or spyware..... could help to see what programs you are running and if they are helping with the slow-down.
e.g.  when AVG is running a scan in the background, you would (possibly) notice things running a bit slower, as this takes about 1to 2 hours depending on how many programs etc you have and the size of them.
List out all your antivirus and anti spyware and firewall progs.
Together with the specs as suggested by Pierre Pierre

[#4]

How about a complete reinstall - sorts all sorts of things out

[#5]

Thanks!
Processor Intel(R) Pentium(R) 4 CPU 2.66GHz
Processor Speed 2.59 GHz
Memory (RAM) 256 MB
Operating System Microsoft Windows XP Home Edition
Operating System Version 5.1.2600
ZoneAlarm Security Suite Version 8.0.020.000
Anything else? Let me know.
I would like only to reformat my hard drive as a last resort as it is extremely time consuming and I am currently snowed under with work.
Many thanks for your help! 

[#6]

The first thing to do is get more RAM http://www.crucial.com/uk/ as the minimum is 512Mb but I would recommend 1GB if your motherboard will support it.
The second is to check the free disk space as you will be using the swap file continuously

[#7]

I have 35.6 GB free disk space.
I am reluctant to buy extra RAM as the computer worked perfectly well before it started to work, well... less well. 

[#8]

Can you open the task manager and post the processes running when you don't have any applications open.
Can you disable Zone Alarm and see if it makes any difference

[#9]

I could, but I don't know how to do a screenshot. If it's easy, I'm happy to give it a try.
I have tried disabling Zone Alarm, and even disabling it at startup, with no luck.

[#10]

Click on Print Scrn then paste into Paint then save as jpg

[#11]

pushing Prt Sc button gets the screen into the clipboard, then using an edit program, save the clip.
Next at the bottom of this input panel is Additional Options  this has a submenu to attach pictures to the bottom of the posting

[#12]

I'm surprised Windows XP runs at all in 256MB.
You are in Windows 98 territory. 

[#13]

Quote

I'm surprised Windows XP runs at all in 256MB.

It surprised me too, and then I saw this:
"Windows XP Hardware Requirements
To install Windows XP 'Home' or 'Professional' onto your new PC, it will need to meet the following specification:
PC with 300 megahertz (MHz) or higher processor clock speed recommended; 233-MHz minimum required;
(Intel Pentium/Celeron family, 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 Gigabyte (GB) of available hard disk space
Super VGA (800 × 600) or higher resolution video adapter and monitor
CD-ROM or DVD drive
Keyboard and Microsoft Mouse or compatible pointing device"
128MB! 64MB min supported........
Regards,
Neil

[#14]

Could not get Prt Sc to work so downloaded a process scanner. Results below:
1 alg.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
2 csrss.exe Microsoft® Windows® Operating Sys... Running Unknown Low Memory Usage Process Scan For Threats
3 ctfmon.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Autostart Scan For Errors
4 explorer.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Process Scan For Errors
5 kservice.exe Delivery Manager Running Low Memory Usage Network Service Scan For Errors
6 launcher.exe Not Running Autostart Scan For Errors
7 lsass.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Network Service Scan For Errors
8 processscanner.exe ProcessScanner Running Low Memory Usage Process Scan For Errors
9 scanningprocess.exe Running High Memory Usage Process Performance Scan
10 services.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
11 smss.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Process Scan For Errors
12 spoolsv.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
13 svchost.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
14 svchost.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
15 svchost.exe Microsoft® Windows® Operating Sys... Running Medium Memory Usage LAN Service Scan For Errors
16 svchost.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
17 svchost.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
18 svchost.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Service Scan For Errors
19 vsmon.exe TrueVector Service Running Medium Memory Usage Service Scan For Errors
20 winlogon.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Process Scan For Errors
21 wmiprvse.exe Microsoft® Windows® Operating Sys... Running Low Memory Usage Process Scan For Errors
22 zlclient.exe ZoneAlarm Client Running Low Memory Usage Autostart Scan For Errors
Thanks again! 

[#15]

It looks as though ZoneAlarm is doing the damage http://www.castlecops.com/t178492-scanningprocess_exe.html

Quote

9   scanningprocess.exe      Running      High Memory Usage      Process   Performance Scan 19   vsmon.exe   TrueVector Service   Running      Medium Memory Usage      Service   Scan For Errors

These are both ZoneAlarm processes
Try Google for vsmon.exe and scanningprocess.exe