I recently reinstalled window xp professional because of some problems I was having. I am still having problems. When I download some software that I previously had and are still using on another PC, once I reboot it is all gone. One software that I was trying to download, I couldn't completely install because of error messages. Right now I went to trendmicro to scan my PC, and it is stuck on the page before it does the scan.

I can get on the Internet. I have Zone Alarm and Kapersky Virus protection.

In your opinion, what could be the problem.

Thanks in advance.

Not recommended to run 2 antivirus at same time - plus you have trend micro
To be honest that is a much bit of overkill

Only ever have 1 AV active with real time scanning.
Even thought both scanners may be happy working together and not conflict during normal use as soon as you get a infected file your PC may clash as both will fight to remove the virus.

here's an article, take info for what it's worth
Smart Computing Article - Clash Of The Antivirus Apps (http://www.smartcomputing.com/editorial/article.asp?article=articles%2F2003%2Fs1407%2F38s0 7%2F38s07.asp)

Personally I would do another reinstall and follow steps provided in link below

How to Format Drive and Install Windows from Scratch
Geek to Live: How to format your hard drive and install Windows XP from scratch (http://lifehacker.com/software/windows/geek-to-live-how-to-format-your-hard-drive-and-install-windows-xp-from-scratch-157578.php)