You will need
  • - email client;
  • Converter.
If you need to maintain the correspondence by e-mail when you reinstall the operating system, use the export function. To do this, start your mail client and select incoming messages of your mailbox previously logged in to your program. Select all the emails you want to save for later export them to the newly installed program.
Find toolbar mail client and find in it the export menu of e-mail messages. After that, your messages must be saved in a file on a removable disk connected to your computer, or any other drive will not be formatted during the reinstallation of the OS.
Repeat this operation for other folders of your mail client. If you're not sure that category of spam mail is just spam, and also make a backup of the files. Will also store the correspondence in the file on the same disk, then close the program and go to reinstall the operating system.
After Windows is installed on your computer also, set your mail client you used previously for electronic messaging. Select import messages from the tools menu, and select your saved file of correspondence connected to your computer disk. Your old messages will be stored in the same partitions as before, or menu, archives, depending on the software you use.
About export email messages in other clients, make sure that the file extension of the messages is supported by the software, otherwise the data will not be read. Here, you'll need a variety of programs-converters. Also, use this manual when reinstalling the email client on your computer. Please note that many of the programs that accept you reinstall without losing user data.