I totally sympathize…
I played with a wireless connection for awhile without too much drama…And I didn’t have alot of problems until I installed Win7.
As was mentioned earlier most Win7 wirelss drivers are crap, and I found that removing the 3rd party wireless manager helped out alot in my case. Signal strength is key, as most wireless setups will throttle bandwidth as signal strength lessens and or becomes unstable. Don’t believe what the 3rd party manager is telling you as far as signal strength. The Windows signal bar is the more accurate of the two.
What wireless format are you using B? G? N? How old is your wireless card and router?
I found that Win7 didn’t like my old linksys setup that I had been using without trouble with XP. I swapped everything out for new Netqueer stuff and things improved dramatically.
Ultimately I spent the money to run a hardline upstairs, and now I have a 50mb wired connection, and just like magic, all the weird inconsistent weirdness went away.