Web browser crashes when loading in vb.net

Im developing an application to load an excel file to a web app and create a google earth file.the excel file loading bit is fine.But when I try to compile the file the web browser shows an error telling that there is something wrong with the connection.This happens when the excel file is bigger than 1MB or so.But when i upload a smaller excel file and compile,the browser runs smoothly.
So obviously there is something wrong with uploading a bigger file.Because it takes more than 1 minute to upload a bigger file it crashes I guess.
But it works fine when a smaller file is uploaded.
I guess its gotta do with the loading time.
Can anyone please help me on this?
Thanks