Your initial post said you had upgrade version, but yours must be update version as you found from the link since it doesn't run from DOS. Mine is indeed the upgrade version which explains why it runs in DOS. You should be able to eliminate the error and install current update version if you can unlock C drive.
Concerning the memory Crucial is higher priced than many other brands, and any brand memory of same type will work. If this is for the Dell Dimension shown in your signature, 512 MB of Kngston memory of DDR2 (PC4200) memory type is only $10.49 plus shipping from
http://www.newegg.com/Product/Produc...0Series&DEPA=0.
Search Newegg for what memory type your system takes if it's not the Dell Dimension 4700, and you'll surely find a better price.
It wouldn't be legal for someone to just send you a copy of any Windows CD. If you wanted to obtain a legal Win98SE Upgrade CD or a Win98FE upgrade CD, they're available for $37.50 and $15.99 respectively from
http://www.amazon.com/exec/obidos/se...rocess=default.