How to change (Dynamic) IP address in Windows 7 or Vista?

Anonymous
2009-12-10T08:06:48+00:00

Had same issue on Vista, upgraded to Win7 and issue remains.

I have a Dynamic ISP IP address, yet it remains as if it were static, everything that use to work in XP and previous versions of Windows no longer works in Vista or 7. I spoke to my ISP (3 times, 3 different techs), they said my IP is dynamic and confirmed it is not set by them as static. They charge more for a static IP, so would not just be giving me this "upgrade" for free. They had "no idea" how to force/change a new IP address in Vista or 7.

PLEASE! Do not bother suggesting to run ipconfig /flushdns, /release, /renew at a prompt to do this like every internet search suggests, THIS DOES NOT WORK. This was done with cmd prompt opened under "Run As Administrator".

PLEASE! Read everything I have already done here before suggesting something I've already tried or have tested and proven to work/not work.

Here are other things I have tried, THAT ALSO DO NOT WORK:

(NOTE: no router is being used, direct connected, CAT5, PC NIC to broadband modem)

-Left modem unplugged 72 hours. No change

-Had ISP send me a new modem. No change

-Uninstalled Network adapter. No change

-Changed IP4 settings from "Obtain Auto" to a made up forced IP, rebooted, then changed back to auto. No change

So, with all of this "old school" stuff already tried and failed, what have they changed in Vista and 7 that seems to keep even Dynamic IP's as static? Where is Windows caching or storing this information so I can clear it, none of the traditional methods work. I absolutely can not stand having a static IP on my home computer.

If you internet search this exact question you'll find what I have, everyone is suggesting the once working methods I've already tried above, yet people using Vista or 7 are repeatedly finding this no longer works.

Here's some more information, that confirms the IP isn't being stored in my modem, or assigned to the MAC address of my NIC...

If I boot this same PC to a LINUX Live type CD, using the same MAC address and NIC it obtains a different IP address everytime it reboots. The issue clearly has nothing to do with my ISP, modem, or PC in general.

If I hot swap my modem to a different PC, the other PC gets a fresh (different) IP address. If this other PC is using XP I can force the ipconfig /release /renew to change its IP address.

If the different PC is running Vista, the IP remains static no matter what I try unless the hard drive is wiped and Vista is reinstalled, then it obtains a new IP on the PC with the clean install, yet it can not be changed after this happens.

So clearly, Windows Vista and Windows 7 are holding onto IP configuration information somewhere and reusing this information when it detects you are using the same internet provider, WHERE is it being stored so I can clear it?

Thank you so much if you have a working solution and actually know the answer, instead of just reading what can already be found by a search engine and reposting info that is no longer valid like everyone else on the internet is currently doing when trying to answer this question.

Windows for home | Previous Windows versions | Internet and connectivity

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

0 comments
Answer accepted by question author
Anonymous
2011-07-14T20:20:09+00:00

I think I have found a solution. It has worked for me so I guess it might work for you.

  1. Find out your IP address e.g. go to a website like http://www.whatismyip.com/ it will show you your IP.
  2. Copy It.
  3. Open Network & Sharing Center
  4. Open the Properties of the network you what your IP to change. In my case it is a EVDO modem.
  5. On the Networking tab double-click TCP/IPv4 which will open a window to edit IP and DNS IP address.
  6. On this window Click on "Use the following IP address" and paste that IP you copied at Step 2.
  7. Change the last digit of the IP to any value above it e.g. if its 192.168.23.123 edit the last digit to something like 122 so that the IP becomes 192.168.23.122.
  8. Click OK until all the windows close.
  9. Disconnect from that network.
  10. Reconnect to that network and if it goes as planned the ISP should force a Dynamic IP. Check http://www.whatismyip.com/ if it has changed. If you cannot browse go to Step 6 and select "Obtain an IP address automatically" then Disconnect -> Reconnect the network.

This worked for me so I'm not sure if it will work for you. Feedback will be greatly appreciated.

Was this answer helpful?

5 people found this answer helpful.
0 comments

71 additional answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Anonymous
    2009-12-30T15:53:58+00:00

    I'm totally lost here.

    by tony1967:

    "I think the dirty, yet to some degree scientific approach I have made certainly proves my DHCP server is a bit more than luck of the draw in assigning a different IP upon request when under other OS's I can change the IP all day long and not be assigned a repeat address, yet under Vista and Win7 the issue of reassigning the same exact IP can also be reproduced every single time. It seems clear here that the thinking behind this change was just yet another effort to dumb down networking confusion for dumb users. The problem I have with this was its now made a significant hole in both privacy and security efforts for individual users. Someone at Microsoft needs to let those of us who aren't just dumb users know how to take back our own control of our privacy and security concerns."

    Obviously you know a bit about networking.  But what I'm confused about is the 'why' part.  The DHCP is just your near side address; your router's far side is your IP address to your house, regardless of what you set your nearside dhcp to be.  As you don't use a router, that's sort of useless, I guess. 

    I run a small network at home, and a very, very large network at work.  At work we use static, easier to track who's doing what.  But at home I use dhcp through a hybrid linksys router.  I've assigned the 192.168.x.x to my main rig (at the router) and done the same for my wife's vista machine; even though it's dhcp, I prefer to have it something more creative than 192.168.1.1.  Bit security conscious.

    The 'why' obviously comes to mind, but you've already stated that's not the issue. 

    I've googled it a bit, can't seem to find an answer to your particular question.  I know you can set it to a particular address using the netsh command, but from what I gather you'd rather have windows change it for you randomly.

    I'll see what else I can find.

    thanks,

    v

    M.V.P. - Desktop Experience | M.C.S.A. | M.C.P. - MS Server 2k3, Network Architecture

    Was this answer helpful?

    0 comments
  2. Anonymous
    2009-12-30T13:42:13+00:00

    same problem!!!

     easy to get new ip on xp but windows 7,this really upset me .

    ip not completely release i think,"cache" hide somewhere.

    any solution, plz let me know advance thx.

    Was this answer helpful?

    0 comments
  3. Anonymous
    2009-12-22T10:23:06+00:00

    *"Uh, where did I repeat what you stated and tell you what you already know?"*What I meant was you clearly read what I already stated and did'nt just tell me what I already knew, like the other person who replied and did exactly that, which I was expecting to have happen and hence the reason I tried to be clear that such an answer wasn't going to solve the problem, hopefully before anyone wasted time trying to reply with an answer that was already tried. I guess I could have written that better, this...

    "Thanks for taking the time to actually read what I already stated before just telling me what I already know Jim, appreciated."

    Should have read more like this...

    Thanks for taking the time to actually read what I already stated AND NOT just telling me what I mentioned does not work Jim, appreciated.

    "You don't say what you're doing that requires cycling IP addresses, but assuming that it's guaranteed to be different from DHCP is just unsupportable.  Assuming that DHCP is offering some meaningful level of privacy and security is placing your hope in the wrong place."

    Does it make a difference why I'd want to change my Dynamic IP at will? Will this in some way make the difference of someone knowing how Windows is now storing this info or not?

    If it wasn't an added layer of both privacy and security then why would any given web browser made allow for deleting cookies? Does it really do any good to clear cookies to protect your privacy and browsing history from data miners if your system maintains the same exact IP address. Allowing a person to change their IP is more significant on the protection of privacy than clearing cookies.

    On the matter of security it again makes a significant difference. If someone was determined to hack a persons home PC then this effort would significantly be simplified if such a person always knew what exact IP they were looking for in an effort to make repeat attempts at determining exploitable holes in the particular system. Since no one has yet to develop the holy grail of computer security we are left to still rely upon multiple layers of protection. The ability to constantly alter your systems public known IP address is just one layer of security that can be used to make such an effort more difficult. Its pretty hard to target and probe a specific computer if its known address becomes unknown.

    Any how...

    I think the dirty, yet to some degree scientific approach I have made certainly proves my DHCP server is a bit more than luck of the draw in assigning a different IP upon request when under other OS's I can change the IP all day long and not be assigned a repeat address, yet under Vista and Win7 the issue of reassigning the same exact IP can also be reproduced every single time. It seems clear here that the thinking behind this change was just yet another effort to dumb down networking confusion for dumb users. The problem I have with this was its now made a significant hole in both privacy and security efforts for individual users. Someone at Microsoft needs to let those of us who aren't just dumb users know how to take back our own control of our privacy and security concerns.

    Was this answer helpful?

    0 comments
  4. Anonymous
    2009-12-18T17:09:22+00:00

    Uh, where did I repeat what you stated and tell you what you already know?  I did not see anything in your writing about the DHCPDISCOVER behavior and didn't myself know that it allowed a request for the old address until I looked into it further.  Maybe you had read that elsewhere, but that sure wasn't obvious in this thread.

    Might I also point out that when the DHCP servers "reassign a new address" at midnight, or by request, or whenever, that "new" doesn't necessarily mean "different".  Nothing in DHCP guarantees it'll be different, and that you are seeing this on XP and Linux is just a likely thing because of your specific DHCP server, not a guaranteed thing. 

    You don't say what you're doing that requires cycling IP addresses, but assuming that it's guaranteed to be different from DHCP is just unsupportable.  Assuming that DHCP is offering some meaningful level of privacy and security is placing your hope in the wrong place.

    On my own (Win7) DHCP system I found my current IP address in numerous places in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters, including under Interfaces that you mention, but also under DNSRegisteredAdapters (see HostAddrs, it's in there in binary form).  I've no idea which of these, if any, might be used by DHCPDISCOVER.

    Jim

    Was this answer helpful?

    0 comments