External harddrives

[dynamic]

I have Dell Dimension 4400
Processor Intel R Pent R 4 CPU 1.6 Ghz
Processor Speed 1.56 Ghz
Memory 256
Windows XP Home Edision

Computer is very very slow.  Have had several crashes in the past and have had to remove and install Windows again with the help of Dell.

I purchased an External Drive and want to upgrade the memory to 512 but have not yet installed.

Can I transfer all data and "programs" to  external drive?  If I wipe out everything can I just reinstall it off the external drive?
Can I use the Norton Wipe Clean?
I am not an experienced computer person... I just click until I get what I need and read alot of forums.

Thanks any advise.

[soybean]

Can I transfer all data and "programs" to  external drive?  If I wipe out everything can I just reinstall it off the external drive?
Can I use the Norton Wipe Clean?

Yes, you can do transfer all data and "programs" to  external drive by using a drive image program such as DriveImage XML.  I'm not familiar with Norton Wipe Clean.  Is that a brand of toilet paper?   

[homer]

Can I transfer all data and "programs" to  external drive?  If I wipe out everything can I just reinstall it off the external drive?
Can I use the Norton Wipe Clean?

Yes, you can do transfer all data and "programs" to  external drive by using a drive image program such as DriveImage XML.  I'm not familiar with Norton Wipe Clean.  Is that a brand of toilet paper?   

just posting to say LOL!