4MB isn't enough for 7.6.1 or 7.5.3/7.5.5 really. It's going to be sluggish. Browsing the web on 4MB...not going to happen, unless we're talking about text-only.

If you want to make it useful, try and find a 20MB module for it.

Here's one which is cheap:

http://www.memoryx.net/pb21020.html

On another website the same 20MB module was $99!