I have an ipod touch with error 1645 it wont restore.

Did you check this thread?

https://discussions.apple.com/thread/4241451?answerId=19384870022#19384870022

i got the same problem(restore), also the worst part is it cant play music, cam dont work, videos online or off dont play, it randamly freezes!!!!!!

do you think apple might replace it? any sugguestions ....

If restoring in recovery or DFU mode does not help and you're out of warranty, I'm afraid you'll have to pay for getting it serviced.

DFU and recovery mode is explained in this post:

DFU/Recovery mode

do you know how much it will be around?,

also my ipod cant shut off proberly, cause it restarts. I think it has TOO MANY PROBLEMS!!! lol

i tought apple would replace it or something, well thanks for the help

Check here:

Apple - Support - iPod - Repair pricing

I found this solution and it worked for me.

1. Disconnect your iPhone cable but leave connected the other USB end to thecomputer. 2. Turn off your iPhone holding the Sleep/Wake button. The red slider bar appears. Slide the bar and wait until the iPhone turns off. Or you could hold the Sleep/Wake and Home buttons at the same time until the iPhone turns off. 3. While pressing and holding the Home button connect the USB cable to your iPhone. It should power on. Hold the Home button until you see the "Connect to iTunes" message. Open iTunes if necessary. You should see the "iTunes detected an iPhone in recovery mode..." alert screen. 4. Choose "Restore".

http://www.fixya.com/support/t14646364-itunes_restore_error_1645