Hello!
I need know to how to avoid the message dialog "Make sure rvhost.exe...." during bootup in winxp... help in this regard

1- open "Run" from start and write "msconfig" in it. Press Enter.
2-In Msconfig window click on the startup tab and uncheck/disable the startup entry for "rvhost.exe".click OK and restart .

Run Malwarebytes Anti-Malware
Malwarebytes Anti-Malware (http://securitynewsfromthenet.blogspot.com/2008/03/malwarebytes-anti-malware-105.html)

Run the anti spyware remove programs spybot Spybot search and destroy spyware and popups (http://securitynewsfromthenet.blogspot.com/2007/03/spybot-search-and-destroy-spyware-and.html) and superantispyware SUPERAntiSpyware Home Edition (free version) (http://securitynewsfromthenet.blogspot.com/2007/04/superantispyware-home-edition-free.html) to get rid of the nasties

Run a complete scan with free curing utility Dr.Web CureIt!
Dr.Web CureIt! (http://www.freedrweb.com/)

In addition to the other fine answers that you have been given, you might also want to click on the links on the bottom of this page to questions that have been similar to yours to see what the answers have been.

Open the task manager and select the process tab then delete the
Rvhost.exe
To remove this error follow these steps:
Start - run - msconfig - startup - disable the rvhost.exe" entry - OK and reboot your computer then scan with good anti virus after updating and anti spyware tool.