Avast not starting

Recently i started my computer running windows XP. when it launched i first got a message from windows at login saying
“The procedure entry point lineGetTranslateCapsW. could not be located in the dynamic link library TAPI32.dll”

my computer then let me log on, but it said that my firewall was disabled. I clicked on avast, but it gave me a second error message saying “The application or DLL C:\Program Files\ Alwil Software\ Avast 5\ aswCmnOS.dll is not a valid windows image. Please check this against your instalation diskette.”

I’ve been looking into this, and i realize that the first one is a problem with my OS, but it seems to be targeting my anti-virus software. I ran a scan with malware bytes, but nothing came up. I scanned with two other programs, GMER, and Findy Kill, both of which i had found after they had been recomended at other locations on the avast forums. However neither yielded any successful results, and the problem is still ongoing. Any help would be appreciated.

Thanks!

PS. I originally posted this on another place on the forums, but i figured this might be a better place for it to go. Sorry

this is the correct place for virus problems…

stay at one place when posting http://forum.avast.com/index.php?topic=80470.0