[devagral]

I had installed windows xp and Obantu on my lappy. First I removed Obantu and then installed windows 7 through ' Advanced ' option. It appears that I could not do it properly and as a result , though windows 7 is working ok, everytime I boot I have to make a choice among the three systems. This is quite irritating as I want to use only windows 7.

Please suggest some remedy. Thanks.

 

[spunk.funk]

If your happy with Windows 7 as is, you can try this method: Remove a Windows 7 Dual Boot, Part I | PCWorld
But since you just installed you might want to download the ISO image for Active Kill Disk and burn the ISO image to a CD or USB Flash with either their tool or IMGBurn in my signature. Boot off of the Killdisk and do a low level format, This wipes out all data on all partitions, so backup first, this will take some time so be patient. Once done, you can install Windows 7 on a totally clean drive.