One of your system programs is busy, more than likely it hung up. If you Control-Alt-Delete and select the msgrv[not responding] and end task you should be able to use your taskbar.
You will need to run a repair setup using your Windows CD. Place the CD in your drive and reboot your computer, wait for the prompt and press "r" to run a repair setup.
I can sure help you downgrade your computer, thats not a problem! You will need a windows 98 boot disk: http://1gighost.net/randyboy/boot98se.exe
Download this program and insert a floppy diskette into your floppy drive and then open the file, it will create a windows98 boot disk. After you have created the boot disk, leave the disk in your drive and reboot your computer.
When your computer boots with this bootdisk you want to select the support for CD-ROM. Then when you recieve the dos prompt you will want to type "format c:" and press enter, type "y" and press enter.
After the formatting has been complete you can insert your windows98 cdrom and type "e:" enter, then type "setup" and press enter. You are now on your way, just follow the prompts and windows will install!
If you need information on backing up files please ask, this answer is written for people who would like a full wipe!
Ok, you created the boot disk and when you insert the disk and restart your computer it tells you that it cannot execute? If this is the case, format the floppy and try to create the boot disk again, it should not give you this problem.
If you wish you could also goto Start>Settings>Control Panel and then "Add or Remove Programs" and select the "Windows XP Uninstall" and click "change/remove" if this option is available.
Let me know if you need further assistance, as I cannot be sure these things will work.
As posted above by "Alvie", I do not recommend you taking this step, as it will cripple your computer even further, it wont help the situation!
In most cases, deskbar is frozen because of some process(es) are using too much percentage of you system resources (memory, CPU, etc.). Those processes might be normal windows process or virus, or spyware, Try the following workarounds:
1. Reboot your computer, hold "F8" during reboot process, and select "Safe Mode with Networking" option.
2. Login and see whether the computer performs better.
3. If you can access Internet now, go to the following website(s) to do online virus scan:http://housecall60.trendmicro.com/en/start_corp.asp?id=scanhttp://security.symantec.com/sscv6/default.asp?langid=ie&venid=sym
If you cannot access Internet, use a different computer to go to Internet and dowload a free anti-virus program:
You may also need to dowload the software in step 5 too.
4. Clean viruses if you find any.
5. Download free anti-spyware program (Ad-Aware) from:http://www.download.com/Ad-Aware-SE-Personal-Edition/3000-8022_4-10045910.html?part=dl-ad-aware&subj=dl&tag=top5
Install and scan your computer, delete spywares you find, if you are not sure about delete all the results, post back.
6. You mentioned EliteBar on your computer, refer to the following web site to remove(you might have removed them with ad-Aware, just double-check):
7. From command line, enter "regedit", explore to:HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
check what programes are in windows startup processes, delete those registry keys that you do not need.
8. Restart your computer in normal mode.
Let's try the above steps first and see how it goes. Note that registry operation is very dangerous, if you are not sure about what you are doing, feel free to ask.
You need to manually switch to your cd drives letter, and depending on how many drives you have it may be "e" or "f". If your CD is in the top drive it would be "e:" and the bottom drive would be "f:", to switch the drive letter you need to type "e:" or your drives letter followed by a colon and press enter, once switched you can type "dir" and press enter to see if you have the right drive, if you do then it should show you the contents of the cd including "setup.exe".
Let me know if there is anymore problems or questions! :)