It is possible to swap windows hosting to linux. You have to create the account in linux first. Take the backup of your account in windows and then contact your hosting provider. They will have to manually transfer the files to your linux account. If you are hosting asp files, very few providers allow transfer assistance. You will have to transfer the files and manually setup the database in that case.
Sreenath Vijayan - Squidix Support @ SQUIDIX.COM (1-855-SQUIDIX)