Security measures

[quaco]

Hello guys!
I´m new here... Excuse me If I post this here, I can´t post anywhere else....
I need your help. I´m a new beginer enthusiast of btc since last year. I don´t minner. I´ve just bought some BTC. I have them distributed at Blockchain e-wallet, MtGox, Btc-e, Virwox, localcoins.com, and in my personal wallet bitcoin-qt installed at my PC at office. I store many passwords of this websites on it. (obviusly, the majority of passwords are codificated)
The problem is I must to send my AIO to a service.
Anybody can tell me, what I must do to be safe, avoiding any possibility of be scammed by persons who will repair my hardware?
Thank you in advance, It´s a pleasure to read some of you. I hope I would be out this "newbie jail" to interact with you.
Best Regards   

[greyhawk]

I store many passwords of this websites on it.

No. Bad Newbie. Don't do that.

[linuxer]

Hello guys!
I´m new here... Excuse me If I post this here, I can´t post anywhere else....
I need your help. I´m a new beginer enthusiast of btc since last year. I don´t minner. I´ve just bought some BTC. I have them distributed at Blockchain e-wallet, MtGox, Btc-e, Virwox, localcoins.com, and in my personal wallet bitcoin-qt installed at my PC at office. I store many passwords of this websites on it. (obviusly, the majority of passwords are codificated)
The problem is I must to send my AIO to a service.
Anybody can tell me, what I must do to be safe, avoiding any possibility of be scammed by persons who will repair my hardware?
Thank you in advance, It´s a pleasure to read some of you. I hope I would be out this "newbie jail" to interact with you.
Best Regards   

Backup your data (Those idiots can delete stuff/format os)
Backup your bookmarks and saves passwords
Backup your passphrase,secrect code etc all those things in a diary
Backup your other data (from roaming folder, if needed)

Remove passwords from browser, clear cookies and history.

Use some desktop lock app/tool

[quaco]

Thank you by your complete and quickly answer, Linuxer!
I will do everything you tell me.
 

[zubelutte]

Remove and keep your HDD.

[gnarl]

Remove and keep your HDD.

This!
Once its out of your sight for an hour, consider it copied and hacked.
I would rather just buy a new ssd than try to secure or delete the data on a system like that.

[J35st3r]

Create a paper wallet https://en.bitcoin.it/wiki/Paper_wallet

Play with it. Import it into blockchain, electrum, armoury, bitcoin-qt.

Make a new one. Do it all again. Get happy with it.

Then send it some (small amount of) coin. Get it back. Learn to trust it.

Now do it for real. Send all your coin.Keep it secret. Keep it safe.

When you need to spend it, bring it back. Spend what you want then send the rest to a NEW paper wallet.

Of course you can keep a float for day-to-day use in an online wallet.

And do the paper wallet properly. Offline computer, live-cd boot.

[Bataleon]

Start using 2 factor authentication wherever possible, like Google Authenticator on Mt.Gox.