Vista Tutorial - System Freezes when uploading

I found lots of posts about freezing problems, but none of them related to
data uploading.

Usually when I'm uploading something the entire system suddenly freezes
making a terrible buzz (like an alarm)... and even if I wait a couple of min,
my only option is to press the shutdown button. I've tried to make lighter
uploads, but it's not about data volume. Even when sending e-mail attachments
it freezes. There's something about uploads that crashes everything. It
doesn't happen ALL the times, but randomly and frequent.

This problem doesn't happen with downloads.

Softwares: e-mails attachs (2.3Mb jpeg using Windows Mail, IE 7 (uploading 2
pics 200Kb each to Facebook), transferring files through Skype (either lights
or heavys)

My laptop: Toshiba Satellite A135
Intel Core Duo 1.73 Ghz
1 Gb RAM
32-bit
Vista Home Premium came with laptop

Connection: DSL 100 Mpbs

Is there a solution for this kind of problem?

Thanks!