The only issue, thusfar, installing IE7 over IE6, was getting an Error 0x8024001D while trying to run Windows Update. The following input I got from Windows Update Forum:

"Go to C:\WINDOWS\SoftwareDistribution and rename the folders DataStore and
Download. Try the update again. You can remove the renamed folders if
everything works.

That is what I got when searched around for error 0x8024001d.

For the benefit of the community reading this post, please rate the pºst.

I hope this post is helpful."

It surely worked for myself and IE7, without a doubt on this end, is running quite smooth....