Hi. So you saying my electrum username/password is completely useless then if i did a reinstall of my computer?
There should be no username. The password is irrelevant if you restore from seed, yes. This is also true if you do not reinstall your OS.
Also is there a way to find out my 12 word phrase is 100 percent right? I wrote it down and have it and pretty sure to 100 percent its right but in case i wrote a wrong letter etc... would that mean i can't get my bitcoins back?
Test it. As I said above you can just keep your wallet file and create a 2nd one. For the 2nd restore from the same seed and see if its working.
Oh no if i send bitcoins to my blockchain... its my blockchain acct not someone elses....
Can you explain the restore the seed before you reinstall? So basicaly once i do that... then once i install electrum 1.9.8 again... then i put the 12 word phrase? Whats difference between restoring it from seed before i reinstall as oppose to after wards?
Its the same. The point of doing it before you reinstall your system is that it gives you certainty that you know how to restore. If this should fail you still have your wallet file protected by the password.
The reaosn why im doing reinstall of windows 7 is my laptop has gotten really slow so wondering if it could be virus etc and internet has lot of issues on laptop.
AFAIK this is a thing of the past. WinXP used to clog up over time, I have experienced similar issues with Win7. This might also be a coincidence since my behaviour also changed. A fresh system is certainly faster, but the question is if it will stay that way if you install the same software you had before.
If you suspect a virus, its probably best to do a scan from a linux dvd, before you use your wallet.
Yes if i put the electrum in my usb... it seems easy b/c couldn't i just transfer that file into my desktop and thus same electrum file? Thus just make sure electrum file is good?
Yes you can also create a backup of the wallet file, you can do this from within Electrum (File -> Save Copy)