- access a user's favorites list
- delete their cache
- delete their history
- remove one item from their cache
- remove one item from their history
- write to a text file on their hard drive
- force them to download a file or plugin without a prompt
- force them to upload a file
- get the filepath of an upload
- adjust their page margins for printing
- automatically print a page without a prompt
- change their default printer
- disable the back/forward buttons
- read a key from their registry
- change their security settings
- automatically run an EXE on the client
- force them to enable cookies
- force them to enable javascript
The simple answer is you can't.
These, and a variety of other questions relating to operations on the client are regularly asked in server-side news groups and forums by beginners, and they basically illustrate a lack of understanding of the http request and response model, and the inherent security built into web browsers.
ASP.NET runs on the web server. Its job is to produce html and javascript which is sent as part of an http response to the client. Once the html has been sent, the web server knows nothing about the client, and it has no access to the client.
