How do i delete my account? I changed my mind about joining this site.

If you have the login info, you can delete the account yourself within the settings. If you dont, you can Flag the account for abuse and Facebook will review and possibly delete the account.

Here, on FaceBook, you can read everything about deleting and deactivating your account. Even when you want to delete your account, first try to delete as much as you can. Then after deleting the account, keep the 14 days in mind. When you go back to the page, the deletion will be undone. They would like to keep as much accounts alive as possible.
Go here, read and delete or deactivate your count:
Search Facebook Help Center Facebook

You can't fully delete your Facebook. You can only deactivate but once you join Facebook again all your information will still be there.

i suggest you defriend everyone, change your details to a random name, delete all your posts, images, messages one by one before you delete/deactivate your Facebook account.

Permanently Close Your Facebook Account
While Facebook can make you accessible to friends and family, it may also make you fear for your privacy online.
Giving out your personal information on a site like Facebook can make you a target for identity thieves.
While you can certainly toggle your privacy settings to adjust how you share your info, you can also deactivate and delete your account so your information is no longer available.
The process can be cumbersome, but it will help you cancel your Facebook account completely.

Sign into your Facebook account normally, then click "Account" and choose "Account Settings" from the drop down menu.
Scroll to the bottom of the Account Settings page and choose "Deactivate," which is the last option available.
This will bring you to a new screen where you may send messages to your friends to let them know you're leaving Facebook.
Click the circle beside the reason you're deactivating your account, which is required.
You can choose from reasons like a temporary leave, having privacy concerns or receiving too much communication with Facebook.
You may also type added notes in the provided field.
You can also decide whether you'd still like emails from Facebook in the future.
When you're ready, click "Confirm."
Sign into Facebook and navigate to the "Delete My Account" page (See Below) if you want to remove your account and information completely from Facebook's files.
https://www.facebook.com/help/contact.php?show_form=delete_account
While deactivated, you'll still be able to sign into your account for administrative purposes and reactivate your account.
A deactivated account will retain all information, photos and notes, but remove them from sight of other users.
Deleting your account will remove your account and information completely from the site.
Send a message via the "Delete My Account" page to let Customer Service you'd like your account removed completely.
Deactivate Your Facebook Account
There may come a time when you need to deactivate your Facebook account.
Fortunately, as with most of the social utility Web sites, closing your account with Facebook is easy.
And if you change you mind, you can always return to Facebook with a simple reactivation process.

Access the Facebook home page and log in using the email address and password you originally registered with (see Resources below).
If you've forgotten you password, click on "Log in" and follow the link to reset your password.
Head to the "My Account" page using the link from the menu.
Follow the "Click Here" link under the Deactivate Account section.
You will be taken to a short form to fill out before you close your account.
Tell Facebook why you're leaving.
Select the radio button next to the reason for deactivating your account.
There is also space to write other comments.
Opt in or out of Facebook emails.
Even if you account is deactivated, your friends can still invite you to events or ask you to join groups.
If you don't want any email from Facebook at all, check the appropriate box.
Click the "Deactivate" button. You will be taken to a page confirming your account deactivation.
Reactivate a Deleted Facebook Account
Head to the Facebook Web site to reactivate your account.
Log in to Facebook as if you'd never left. Use your original email address and password.
Check your registered email account for a confirmation email from Facebook with directions on how to reactivate your account.
Follow the link in the email.
You will be taken to your home page, which will appear exactly how you left it.
All your settings and events are intact upon reactivation.
All you have to do is start exploring again.

Your primary Facebook email address is the address you use when you log in to your Facebook account.
Additional email addresses can be listed on your profile as well if you chose.
Changing, adding or deleting email addresses on your Facebook account is easy to do.

Log in to your Facebook account.
Select the "Account" menu in the upper right corner of the screen and select "Account Settings" from the drop-down menu.

Click on "General" from the list in the left panel of the Account Settings page.
Click on "Email" in the main window to expand the section.

Click "Remove" next to any email address to delete it.
Click "Add another email" and type a new address into the space provided.
Click the radio button next to any email address to designate it as the primary Facebook email address.
Click "Save Changes."

Facebook sends a confirming email.
The change does not take place until you open the email and confirm the change.


http://www.facebook.com/help/?faq=162801153783275&ref_query=email+ad
How do I add or remove an email address from my account

Step 1:
Deactivate Your Facebook Account b> There may come a time when you need to deactivate your Facebook account. Fortunately, as with most of the social utility Web sites, closing your account with Facebook is easy. And if you change you mind, you can always return to Facebook with a simple reactivation process.

Access the Facebook home page and log in using the email address and password you originally registered with (see Below). Sign into Facebook and navigate to the "Delete My Account" page (See Below) https://www.facebook.com/help/contact.php?show_form=delete_account If you've forgotten you password, click on "Log in" and follow the link to reset your password. Head to the "My Account" page using the link from the menu. Follow the "Click Here" link under the Deactivate Account section. You will be taken to a short form to fill out before you close your account. Tell Facebook why you're leaving. Select the radio button next to the reason for deactivating your account. There is also space to write other comments. Opt in or out of Facebook emails. Even if you account is deactivated, your friends can still invite you to events or ask you to join groups. If you don't want any email from Facebook at all, check the appropriate box. Click the "Deactivate" button. You will be taken to a page confirming your account deactivation. Reactivate a Deleted Facebook Account Head to the Facebook Web site to reactivate your account. Log in to Facebook as if you'd never left. Use your original email address and password. Check your registered email account for a confirmation email from Facebook with directions on how to reactivate your account. Follow the link in the email. You will be taken to your home page, which will appear exactly how you left it. All your settings and events are intact upon reactivation. All you have to do is start exploring again.
Deactivate my account
http://www.facebook.com/help/?faq=13015

Honestly, this does not sound like an issue with joining facebook at all. You have a deeper issue. Sounds like a password somewhere else got compromised and then your other accounts got hacked. (same password for email/facebook/etc?) Now it appears that your computer possibly got hacked and files and hardware are damaged. This is not something that happens from signing up for facebook.

dear friend,
Step 1: Before You Start

• There are some things to keep in mind before you join Facebook.

1. Signing up for an account is 100% free.
2. You need to be 13 years old older to join.
3. You need a valid email address to sign up for Facebook.
4. You can only use the same email address once; if you already have a Facebook account and want to create an additional once, you need to use another email address

• Step 2: Signing Up
  • To create a Facebook account, you will first need to sign up for one.
  1. Visit Facebook's homepage. You will be greeted by the sign up field.
  2. Type in name, email address, password of choice, *** and birthday.
  3. Facebook will send you a registration email next. Log in to your email account and click on the link in the email.
  4. After signing up, you can start to customize your profile page and add friends.
  5. When you first sign in, you will be asked to join a regional network. If you choose to do so, your profile page will be accessible to others in the network.
• hope this information is fine,if still you have problem then you can ask me again & if you like please vote for me
  enjoy & Cheers