unable to uninstal IE7 beta

hi,
i recently installed IE7 beta version which has run into problems like if i try to open a favorites folder the browser window shuts down.i want to uninstal & reinstal the latest beta3 which i downloaded from microsoft website.however iam unable to uninstal IE7 because there is no entry in 'add/remove programs'.when i try to instal IE7 beta3 on top of the previous instal i get a message asking me to uninstal first.
any suggestions anyone??
thanx
ramkumar