help with memory upgrade

[chpstckdrpkck9]

I am planning on upgrading my memory on a Dell Dimension 4550 and I need help in compatibility
Will this be compatible:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145407
or
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145026

I went to crucial.com
http://crucial.com/store/mpartspecs.aspx?mtbpoid=750ED13FA5CA7304

It was cheaper at newegg.com, but i didn't know if it was compatible
if it is not compatible, could you help me find one (im looking for 512MB)

 

[Cromewell]

Any of the above are compatible and should work fine. I would go with the one of the sticks that have rebates since even though they are a pain, it makes them $10 cheaper.

 

[viper110110]

second one as it will work and is slightly cheaper